I know what everyone says, once you clip in, you never unclip, but my dad has recently added clip-less pedals to his bike, and the idea of not being able to wear my everyday shoes, isnt so appealing. Recently been looking into Speedplay Drilliums, or Brass Knuckles.

Mostly doing just neighborhood riding, and whatever air I can find, but looking into more serious downhill riding.
Heard that serious Platform pedals is the way to go for bigger air, which is one thing I'm very into currently.
Any tips?

This subject comes up often. I like to refer to a bicycle manufactures article ( The Shoes Ruse ) by Rivendell Bicycles, google it for a different point of view. Then do as you would like. There are many opinions, most preferring clip less. For me, well I prefer to use one set of shoes YMMV

For road biking, it's clipless or your a poor Fred. For MTBs, it's not the same. It's more like a saddle, whatever you prefer. I went clipless, then went back to flats and regretted it almost immediately when my feet flew off the pedals. I compromised by buying the flat on one side, clipless on the other pedals. Now I've got both on the fly. If I need to go flat, I unclip, spin and put the foot down on the flat. It's not perfect, but I'm sticking with it. Still, I see a lot of really good MTB'rs going with plain old flats wearing sneakers. Whatever you prefer. But I would try both before deciding.

Used my dads bike with clipless many times, just feels restricting, and impossible for big jumps.

Well, seems like many(most?) downhill guys use platforms with pins, typically with something like Five Ten shoes.
I'm just into trail-riding--no aggressive downhill for me---but I don't care for clipless, so I use a pair of VP Thin Gripsters pedals with Five Ten Freerider shoes, and my feet never come off the pedals unless I do it intentionally. That combo REALLY sticks. I also like that I can just hop on the bike and go with whatever other shoes I might have on if I'm doing a mellow ride with my kid.

Not neccessarily, a lot of dh races run clipless. Just depends on conditions.

Pinned platforms for all my bikes road or mtb. I HATE the feeling of feet attached to pedal. Pins keep my shoe from slipping but give me the option of lifting off if I want to.

I personally use platform, because I like the idea of not always going down with my bike.

I like being able to bail too. Plus, does anyone besides me not put their foot down once in awhile?

Get double sided pedals.

Nashbar.com sells some called "SoHo" pedals & they put 'em on sale for $30. Flats on one side & clips on the other.

Also, when you buy shoes, make sure you buy mountain biking shoes. That way, you can still walk like a human when you get off the bike without having to change your shoes.

I have double sided pedals & love 'em. If I take my bike on vacation with me to the beach, I can ride it wearing flip flops to go get ice cream. Later than night, I can go blazing up & down the strip on my own with the clips. Best of both worlds.

Totally--sometimes I find myself "dabbing" at rocks or logs if I'm working my way slowly through a particularly tight, tricky section with tall obstacles. Can't imagine doing that clipped in (but I'm sure it would just take practice....)

I can see me not being able to get my feet loose and busting my butt. I'll stick with platforms.

Platforms here. I got busted up pretty good once and still needed to kick a foot off the clipless. That was a horrible moment.

I race downhill on platforms; but I'd say the mix of platform/clipless users at any given race is about 50-50. Very much a personal preference thing for that. But if you're looking at messing around more with dirt jumping, I'd definitely stick to platforms.

This ^^^

They even make DUAL sided combinations with clips and platforms on BOTH sides like these: Shimano PD-M424

YES, there is a lot to be said about getting hooked up on your pedals when baling to stop suddenly but there are distinct advantages. More power to your pedals for one thing - and not as MUCH gain as you think, I would guess you get maybe 10% tops more effort into each stroke than without clips. Proper foot placement is my reason, i have a bit of neuropathy in my feet and find that if I ride without clippless my feet are all over the place, sliding off, pedaling with my heel or instep. Let alone getting my feet bounced off the pedals over a rough patch. For me it is generally SAFER to ride clipless.

Same with me... being connected to the bike is an undeniable benefit. It makes bunny-hopping over obstacles that could puncture your tires a ton easier, too.

That being said, you gotta practice clipping in & unclipping. You have to be very intentional about it. Also, if you ever adjust the tension on the clips, be sure to re-practice unclipping.

Afterall, you'd hate to pull up to a crowd of 20 pretty ladies at your son's school on your pretty bike, wearing your go-fast gear and do the slow-motion dork-fall because you forgot you tightened your clips & couldn't unclip.

I can precisely remember what I was feeling while falling. Still have the mark on my shin and I'm not proud of that one

Flats for me. Rode clipless for a couple of seasons but never felt really comfortable. I didn't find any benefit and I like the feeling of being able to get my foot down or get away from the bike. We ride pretty steep gnarl here and I climb and jump as well with flats. I think the quick acceleration available with clipless may be missing but it a minor issue for me.

All that being said, two of my buddies ride clipless and they are super riders. So I think you should try both and go with whatever feels best.

I use pinned flats and my feet rarely move on the pedals. I have never felt the need to be attached to the bike on the trails.

Pinned flats for me too. I pair them with some 5.10 freeriders and I don't have any troubles. I've tried clipless and it just feels weird to me and I don't like feeling attached to the bike.

I don't have the experience of a lot of the other people here, but I decided to go for the clip less mostly for fitness to workout a lesser used set of leg muscles, plus the extra efficiency. I was quite worried I'd be going down on the trails with my bike, but the extra control I had from being clipped in kept me much safer. Much easier taking turns, bumps, and to bunny hop obstacles and still be connected. I also dialed down the tension on the clips to minimum so clipping out was as easy as possible. I've never yet clipped out when I didn't intend to and have had one close call where I managed to clip out and get my foot on the ground as I was on the way down. Yeah it takes some getting used to and some practice clipping out, but seemed worth it to me. Definitely to each their own though.

The things I absolutely hated when I rode eggbeaters for a day was 1) the clips were way up by my toes and I couldn't use the pressure from the arch of my foot to control the rear end, 2) my feet would rotate slightly in the mechanisms, which made me feel super unstable, and 3) when I needed to abandon ship at a split-second's notice, I couldn't.

I use BMX flats. Diamondback Bigfoot. Plenty grippy. I'll take an occasional whack on the shins over significantly less control any day of the week.

In case any were wondering I went with the Shimano PD-MX80's, flats with pins. Work like a charm...

So are cages just a terrible idea then? I feel like they'd be easier to get out of than clipless, but still offer some of the benefits.

In general, they'll be harder to get into and out of than clipless, particularly if they're tight enough to actually offer some of the benefits. Plus you'll need to flip them to get in, and if you don't have your foot in during a technical section and decide to just use the platform side, the cage will probably smack off a rock since it'll be on the underside of the pedal.