GT3:
GT3 was a great game in it's time, surely. It was the first game on the magical PS2, and had amazing graphics, realism, and created a wonderful driving experience.
But there were downsides, such as only 150(ish) cars, and the removal of some tracks left some fans in dismay, the removal of any form of racing modification, and increased racing length left others wandering far from their game disc in fear of racing a 100hp, FF for 45 minutes around a test course at 100mph.
But the downsides, have also been looked at as upsides, such as the racing length, hardcore fans, (such as myself), generally enjoy the longer race length, and removal of a billion 2 and 3 lap sprints. They also enjoyed all the cars featured, and were happy to see some of the slower cars removed, and either didn't like the missing tracks, or simply enjoyed the fresh graphics enough that the sacrifice was worth it.
Physics The physics of GT3 caught many by surprise, from spinning tires up to 90mph in front-wheel drives, to 160+mph burnouts in 1100hp Dodge Vipers. The FF cars understeered far more than in GT1 or GT2, attempting to give off a feel of realism that had been unrivaled by any
Gran Turismo title yet to date. However, namely on FF's, the wheelspin was simply to much.
GT4:
GT4 came out with statistics in your face, 650+ cars, up to 100 tracks, including the addition of many real life tracks, including the smash hit Nurburgring, among others. GT4 included most of the cars people liked from GT2, that went missing in GT3, bringing back muscle cars, many FF's, a new form of racing modifications, albeit ugly, a functional one. And all-new classics, all while adding to the already long list of cars, racecars, and even adding some trucks/suv's.
The amount of races in GT4 increased from GT3 about tenfold, even including famous 24hr races on Circuit De La Sarthe, and The Nurburgring Nordschliefe.
The downsides included complaints of horrible AI, massive tirespin, and the inability to race FF vs FR, coupled with overly long races, 3 of which take 24 hours, unless you have B-Spec race them, which still takes 24 hrs, unless you stay with it the whole time, and use the 3x speed mode, which still takes 8 hours. Also included was a 9 hr race, and 8 hr race, a 5 hr race, and a 4 hr race.
Physics GT4 introduced a totally different driving experience than GT3, with more realistic handling, braking, and required feathering of the throttle. The major downside is the amount of wheelspin, or, more specifically, the lack of forward momentum produced by wheelspin, which makes some cars unable to compete with full power, and renders Front-wheel drive virtually useless, against anything other than more Frontwheel drive cars.
GT4 is also the first GT game since GT1, that has had numerous improperly modeled cars, mostly being American, and European. From the Dodge Viper SRT-10's powerband, to the Saleen S7's wheelspin, across the sea to the M3's and Z4's outrageous pricing, among many others.
All-in-all, I'd say GT4 is generally more realistic, given the better driving of all MR's, RR's, and FR's. The 4WD sacrifice is big, being nearly knocked out of competition from rear-drivers, though I must say FF was knocked out of competion already in GT3, for the most part.
And while I can knit-pick GT3's physics to hell, naming most every aspect of driving to be imperfect, the only real problem in GT4 is the forward thrust generated by wheelspin.
The problem is, while GT3 had many small, but significant problems, GT4's single problem is massive, and ruins any chances of really competing in a fair, fun race with front drive cars, unless only racing other front-drivers. And this could be the deal-breaker, if GT3 hadn't already rendered FF's impotent, which means all I lost in GT4 was a small crowd of 4WD's, which I don't care for to much anyway.
I'll take GT4, since FF's have been gone for me since GT2 anyway.
WOLFE
I have a couple of questions for you.
1. How does the suspension not move in GT4? mine does, quite a lot on some cars, most notably the Viper's.
2. Wheelspin - You can't make cars spin out? we must be playing a very different game, or you must simply not be on the edge, because you can spin many cars out, unless, that is, if you're using S2's, than many cars won't do burnouts after 1st gear, but that kinda sounds realistic for a 280HP, RWD car to me.
Oh, and GT3 had N tires, they were just called "simulation".