Not since the 90's on the old nfs games on pc, so just gamepad. I dunno, when I drive my personal car it seems like it can brake fast and not slide all over the place and it's only in the ~400 hp/torque range, it's easily controllable at speed and it's not even a racing car (Magnum SRT8). On all these racing games it seems like braking takes forever and the cars are always skidding and sliding, it never feels right to me, even in expensive sports cars. I haven't raced professionally but I'm in LA so doing 90+ mph isn't exactly a rare thing.
Braking can be very easily measured objectively though, and I've yet to see figures that prove the braking distance is completely wrong in GT5. Also, braking in a straight line is generally easily controllable, but weight distribution matters here, and I did hear that many cars have been set up a bit too aggressively in GT5 (there are advantages to this for certain racing conditions). I can look up some comments on that if you're interested - I think that's the problem you may be experiencing. Cars skidding and sliding, or a similar feel, typically has a number of causes when under braking:
a) abs is completely off. Now braking too much blocks the wheels, and you'll slide a lot. Some sims do this too much (Forza 3 waas a little weak in this area, but Forza 2 was much worse) and regaining grip is often not as well modelled (is also one of the more difficult things to model), but GT5 handles this pretty well I think. No abs is pretty rare these days in normal cars. I had an Alfa 155 1.8i as my first car, and that didn't have it, but even then I only ever had it block the wheels and slide under wet circumstances (but one of those times was at very low speeds, and I still wrecked the car partly as a result of that)
b) asm is on. You're braking in the corner, the car loses grip, the asm cuts in, and sometimes this feels 'weird' (you're no longer in control)
c) as mentioned, lousy / too aggressive brake balance. Again, I've heard some people complain about this in GT for many cars. I haven't had much issue with it personally, but probably just because of my driving style.
Here you tell me which is the more normal behavior since you've raced on the 'ring (pretty cool by the way). I'll use GT5 and Shift 2 to compare since I can't remember Forza anymore, been too long. One big difference in behavior on the two is how bumps are handled. On GT5 you can go over bumps at low or high speed and barely feel them, like cutting corners really tight or whatever, they are mostly a non issue. Shift 2 is the polar opposite in that regard, you really feel them and can lose control if you go over them too fast. Now that is one real life test I haven't done as I'm not about to start going over sidewalks in my car at 60+ mph, so I have no real life counterpart to compare to. So which of the two is more realistic? I don't know if you've tried Shift 2 but try it over bumps and compare it to GT5, that's the biggest difference I've seen between the two so far regarding driving behavior.
It is all a matter of settings again, although I can't vouch for Shift 2 because I haven't driven them. The spring has bound and rebound settings, and depending on how you set them up bumps all but disappear, or are actually magnified. The height of your car is also important - if you actually crash into the bump with the bottom of your car that has pretty big consequences.
Although I haven't played it, I do know Shift 2 has extensive setup options, and also allows you to save and load different setups (something which GT5 currently lacks, when older GTs did have this option), so that's what I would look at first. The kind of setup that cars come with when you first drive them can be very different across games, partly because it is as much a preference thing as anything else. I've seen people drive similar times both in reality and in games with vastly different setups.
From what digi says, I'm guessing that Shift 2 has made similar mistakes as Forza 2 in its modelling of grip while turning.
