I don't agree with this assessment at all. I've used pegged platforms before, and while they prevent foot slip pretty well during the power stroke-- with certain types of shoes; textured rubber sport shoes work better than hard plastic outsoles on cheap dress shoes-- they still allow the foot to "walk" around on the pedal, either by accidental displacement over rough, bumpy patches, or by deliberate displacement because you want to stretch your muscles or whatever.

I'd hope it would be needless to say that losing your optimum position on the pedal is a bad thing, but I'll go ahead and say that it can be downright unsafe if it were to happen at a crucial moment when you needed to maintain absolute bike control, such as accelerating out front of traffic through an intersection. I use that example because it happened to me on a wet, cold evening several years ago. I'd switched from clips/straps to aluminum platforms with pegs because the clips were scuffing my dress shoes, and as I was sprinting off a stoplight to take clear position on the road ahead, my foot slipped off the pedal, and I fell forward on the bike which lost its line and wobbled dangerously in front of the accelerating traffic. Thankfully I didn't go down, and was able to recover, but it was probably as close to death on the bike as I've been (without actually being hit by a car).

Toe clips, on the other hand, provide absolute retention and optimal foot placement in ALL situations. There is no "almost as well", no "nearly as good as", or "just about as well as" business. They get that part of the job done as well as clip less pedals, which for their part, trump clips when it comes to ease of entry/exit.

All systems have their pluses and minuses (except traditional cleat/clip setups; why someone would choose that is beyond me!), and so depending on your needs, fears, abilities, shoe type, and riding conditions, one may make more sense than the others, but for me (and I'd guess most riders), there is no one, single ideal pedal. I use clips/straps on the commuter, clip less on the trail and road bikes, and platforms on the play bike and coffee-cruiser, the former pegged.

To the OP's question--finally!-- I'll say that I run my clips at two different "snugnesses": my right foot, the power leg, I keep snugged down pretty well, such that it takes a fair amount of tugging and wiggling to get it free (depending on outsole; some sport shoes have flared outsoles that grab the straps, others are grippy on the bottom, some smooth, but in all cases, I'd call the fit snug). I always start off with that leg, though, and I never put my right foot down, so there's no issue in having that foot so secure, and I like the assurance of knowing that I can count on that foot to stay planted no matter what I do. I don't have to worry about or think about my foot when I'm bunny hopping potholes, curbs, or whatever.

My left foot, the one I put down when I come to a stop, I run looser, so that I can get it out more quickly and with less effort. I guess I'd call it "finger tight," as I pull the strap down just enough to contact the top of the shoe, but not compress or put pressure on the sole. I still enjoy pretty consistent foot placement, though there is some side-to-side "walk", but very little. Of course forward movement is limited by the clip, and vertical movement is almost zero.