Instead of opinions, lets lay down FACTS about each game as to why one is "better" than the other from a semi-unbiased point of view (I own both - as many users do). This is very fair to do so seeing that GT5 Spec 2.0 clearly was released to compete with the launch of FM4.
Things GT5 does better:
- track accuracy (judging from more accurate lap times) & attention to detail
- time & weather change (for certain tracks only)
- variety of racing (dirt, snow, and tarmac + karts, NASCAR, etc.)
- sound physics (Doppler effect, echoing, etc.. Although I mention this, I haven't really noticed these effects in my FM4 play-through thus far. Someone please correct me if I'm wrong)
- creation of custom tracks
- photo-mode has more features
- ONLY with regards to PREMIUM, graphics are much better
- this last point is sort of game related, but GT5 has proven its ability in "training" ( / assisting )(semi-) pro race car drivers
Things FM4 does better:
- cleaner, more focused car roster
- offers cosmetic tuning on almost all vehicles (both games have in-depth mechanical tuning w/ a slight edge to FM series)
- car sounds are more raw and submerge the player more
- has additional online features such as leader boards, rivals mode, auction house, and clubs
- all cars (except for the "beloved" unicorns) are available to purchase
- more freedom in career mode
- prize system is more personalized
- Autovista (although its only for about 25 vehicles, it is much more innovative than that thing called "Museum" in GT5)
- cosmetic damage (since both have great mechanical damage)
Both games offer 16 player online, lobby systems, physics that many may call "
Sim-arcade", and their own approach to mini-games; be it
License Testing and
Special Events in GT5, and
Bowling and
Tag in FM4.
As for the A.I. - I don't really even want to go there. If you want to RACE - go play multiplayer (in either game). I am yet to experience an M. Rossi moment like that of FM3, and in GT5 I do find the A.I. intelligent enough to know I'm ton the track (as many would like to argue otherwise). The
A.I. is enough in both games to play against (using Arcade mode in GT5 for comparison since A-Spec hasn't seen an improvement).
In conclusion, I find that FM4 better appeals to a car enthusiasts needs/wants as I find it captures the current car culture much better (especially with a more in-depth inclusion of Top Gear a la Jeremy Clarkson). GT5 on the other hand appeals to those who are more into the history of vehicles (inclusion of variations of the same cars that have received minor mechanical changes which allows players to experience the differences), or just want a great drive/race (well at least it fills my desires for driving/racing much better).
And yes. Although I had wanted to stay away from opinions, the last two paragraphs are littered with them. Enjoy
P.S. As for wheel support, MS doesn't seem to give/get any love. A proper "entry level" wheel costs an arm and a leg.
P.P.S. One more opinion, I absolutely hate the different surfaces in FM4. They act extremely unrealistic, slowing cars from +200km/h to 0km/h almost instantaneously. However, this is a good balancing mechanism to eliminate shortcuts. Take some to gain some?
P.P.P.S. One more thing, there is an in-game steering aid that cannot be turned off in FM4 for some reason :S Please fix this :S