me, i'm too heavy to do any hill damage but I seem ok on the flats.

Downhill.

The hills are where it counts.

Relative to the people I ride with I'm definitely better in the hills for a few different reasons.

1) - flats bore me pretty quickly. Nothing worse to me than a 10 mile stretch of road without a curve or rolling hill. I can keep pace with the peloton no problem, but man I hate those long hard slogs. Throw in some wind and I don't enjoy myself at all.

2) - when I see a hill I want to be the first person to the top. It doesn't matter if its a known sprint point or not, I want to get up it as fast as possible.

2) - on group rides people tend to remember who is always putting in good efforts on the hills. Making sprint attempts for county lines is great and all, but usually 75% of the people I ride with are all sprinting. Nowhere near as many people have the desire to push themselves past an easy spin up any given hill.

So I'm better in the hills for sure, and its all because of my mental approach and how I view them. I see them as a challenge that, when I give my best efforts, over time I will become a much stronger cyclist. I don't have that sort of mentality in the flats.

Hills.

5'10" 155 all arounder. I prefer flats with a 50mph tailwind.

I'm bad at both.

I love flats with a strong headwind. I do weight training over the winter, so I'm sort of bulky.
Its harder to drop someone on flats but at 5'4 I doubt I'm providing any decent drafting. When I sit behind someone over 6' it feels like I'm drafting a truck.

I used to be good on the hills but put on some weight.
Always been pretty good downhill.
Flats I am mediocre.

Working on getting to be a better all arounder, rather than my old goal of being a goat.

Big picture? None of the above. Compared to the guys I ride with? Hills.

Flats. I live for crosswind days.

Dale Stetina won the Coors Classic on a flat stage. I think it was Denver to Chyenne. The winds forced echelons to form. He was in the lead group with the whole East Germany National Team and some other Europeans who knew how to ride in the wind. They just rode away from everyone else. He made enough time take the lead and win overal.

Flats. Too heavy to be really good on hills when road riding. But I can climb pretty decently while riding a loaded touring bike. What I hate is any sort of steep descent.

Clyde. Flats.

GH

I like the flats because I can get into my drops n go ,but I know you've gotta do gain so I often ride hills ,since I'm a heavier guy I pass every one going down ,and start spinning going up the hills n drop spin drop drop a gear spin spin drop drop spin till am almost at the top then I'm Mary Poppins spinning heart not outa my chest n slowed to bout 8-10 mph n then recover on the tops

I think I'm better in the hills mentally, even though I'm physically more suited to the flats (6'2", 180-185). I accept that hills hurt and don't pay attention to that as much. When I have to work on the flats where the pace normally wouldn't be a big effort it's harder to ignore. My last ride had a bit of misunderstanding about the route and a few guys made a wrong turn. Two of the three caught back on, but one was only able to make it halfway back in the headwind and I dropped back to pull him back in. It was less watts than the two contested hills on the route for about the same length of time, but it seemed like an eternity and felt like it took a lot more energy.

Up hill.

It's genetics. I'm 5'10 and in good shape weigh 135-140 pounds (138 this morning). That gives me a decent power to weight ratio (currently 3.5W/kg at threshold) for good up-hill performance, but mediocre power to CdA ratio only netting 20.4 miles in an hour riding at 94% solo on flat ground. I don't have good anaerobic power either.

I am 6' 1" at 203 lbs and am not good at much but will push like crazy up hills and on flats. I try hard but do not have much ability in either.

As for going downhill, I can create a draft strong enough to suck a mustache off your face!!!

Plus I tend to have to break for the skinny guys since I can get up to one hell of a speed going downhill rather quickly.

Lol.
i am just as slow on hills as I am on flats. Of course I live in North Florida and our hill (yes, singular)is merely an overpass.
I really would love to ride some hilly areas just to do it. It seems like fun and a great way to not only push yourself but become a better cyclist. Alas, I hate the cold so I will probably not see hills anytime soon.

Like Drew, genetics for me. I was a slow and clumsy kid/young man at every sport I did until I discovered I could climb. I"m a mountain goat. Good for very little else. That discovery drew me into racing. (That and the ability to draft.) Now, many years later,it is still my joy. I am doing far less climbing this year, but that is because I am going through PT so I can get back into riding as I love for the rest of my life. (Achilles, etc.)

Ben

And not resting on that downhill on the other side.

+1 on all three

Hills.

Whenever on a group ride it seems like everyone else slows down on the climbs.

I am better at the flats, and short steep accents. I am carrying about 20-25 lbs of weight food,water and tools so hills are not easy and a 36/46 chainring to 11-32 cassette.

I am really better by a huge difference on hills at 185 cm and 76 kg im normal to lightweight.
But the main reason is i cannot hold a decent cadence on flats especially behind others, i struggle to follow them sometimes when they go at about 28 km/h.
I also live near lots of mountains and i train mostly on hills when im alone.