Genre choices always seem to boil down to a field of two. Notably Quake3 - UT, CS - Tac Ops, Pentium - Athlon, Tea - Coffee, Kylie - Danni and now GP4 - F12002. So, which is the premier F1 sim? I've no idea, they're both great. Much like Kylie & Danni covered in whipped cream. They do have their own strengths & weaknesses though. Oh, and I've got both, so no bleating that I'm biassed either way.
Interface: F12002: 9/10: Very friendly, everything in the right place & easy to find. Has a great 'restart race' feature should you screw up in the first corner :) Polished. GP4: 8/10: Could be much better. Suffers from bugs where the menus go crazy when used with a split axis pedal wheel. This also causes the infamous black screen of death when starting GP4.
Features F12002: 9/10: Basically everything, I'm sure the kitchen sink is in there somewhere too, even pit babes, although their nipples don't stick out when it's raining ;). The pit crew is a nice feature but better done in GP4. No mid race save. Bad boys ISI. GP4: 8/10: Last years teams, drivers & tracks. Not too much of a problem as the modders are already at it producing 2002 car skins. More of a worry is lack of certain rules like stop/go & drive through penalties. The pit crew is light years ahead of gp3, full 3d & all motion captured etc. I' ve heard they can even make mistakes. The models suffer a bit from cabbage patch doll faces where the devs have saved a few polys. You can save mid race in GP4, unlike F1
Car Models: F12002: 8/10: Look very realistic, with 3rd party baccy skins that would go up to 9 or even 10/10. Car specific steering wheels etc. GP4: 8/10: A bit low polly when compared to f12002. Cockpit still has what looks to be a generic GP3 steering wheel.
Damage Modelling F12002: 8/10: Much better than f12001, when wheels & parts break off, they now have proper collision detection. GP4:9/10: Wow, more detailed than f12002. Stunning. Broken bits still have their own shadows. Nice.
Textures: F12002: 8/10. Some very nice work, especially in the grass and tarmac department. Lots of detail. GP4:7/10: There's some very low res / uniform textures in there for the tarmac and grass. Looks a bit like F12002 set to low detail in places. Some of the car textures are tiny & causing worry in the modding community that a _good_ season '02 may not be possible.
Weather: F12002: 8/10: Great, except wet weather. Visibility is reduced (which is good). Lots of spray etc, but no we reflections. I guess ISIs engine just can't handle the environment mapping required. GP4: 8/10: Great, in different ways. Wet weather seems much more realistic, however it seems permanently sunny. Even when raining. Visibility not reduced by much. Environment mapping veeery nice.
General Graphics F12002:9/10: very immersive, good use of lighting, very well textured but looks a bit flat compared to GP4. GP4: 9/10: Not as well textured but much better lit than F12002. Environment mapping looks wonderful with the bump and environment mapped track reflecting the sun in different ways. Heat haze and helmet view are nice bells & whistles.
Tracks F12002:8/10: Seem great, lots of bumps seemingly in all the right places. Rumble strips produce nice effects. GP4: 9/10: Amazing. GPS data really show through. Cambers & slopes much more true to life than f12002.
Sound F12002: 9/10. Great. Lots of chatter from your pit crew, good engine sounds. Great audio feedback when your tires are right on the edge of grip. Passable music and a good all-important roar from your own engine. Ambient sounds good, including hearing other cars elsewhere on the track. GP4: 7/10: Bit of a let down really. seems really quiet compared to F12002. Not much pit crew commentary and very hard to hear. 3D sound seems to incur an inordinately high processor occupancy hit though.
AI: GP4: 9/10. Fantastic. Cars will draft you etc, and not budge on the racing line unless you really have the edge on them. ie. Bump them and it's your fault :) F12002: 7/10: Nice but dim. Often you'll see cars wading over the grass just to keep some personal space around them, pitting at the wrong time or at all in a 3 lap race.
Driving Aids: F12002:9/10 There's lots to choose from, ABS, traction control, steering help etc as well as the new stuff like launch control. Most are applicable in a low/med/high setting as opposed to just on or off. GP4: 8/10: Less aids here and you can only toggle them on / off. It does have suggested gear and show racing line though, which are great for learning a circuit while retaining full control.
Force Feedback: F12002:9/10: Smashing. The track, rumble strips, bumps, slips & skids are all transmitted very realistically. Crank up the strength and you really have to fight with the wheel sometimes. Even better it's fully editable. I've knocked off the engine vibration at rest & upped the force of the rumble strips. Getting on the grass could do with a bit more loss of control though. It's almost as sticky as the tarmac :) GP4: 7/10: Not in the same league as F12002. Forces are generally weak and not as numerous or well used as F12002, not editable either. Off track effects are better tho.
Modability F12002:9/10: You can do almost anything to change the game, very easily. Most of the engine parameters are held in plain text files, so you can tweak the AI, weather, draw distances, force feedback effects. The list is endless. Models and textures are easily replaced. Check out the GT mod to see what is possible. GP4: 6/10: Much less scope here. Even the car textures are much harder to create and import. See the GP4 section on http://www.emacf1.com for why.