honestly i havent used the g25, (i have the 911) and all i hear is people rave about the g25, honestly, im not a hardcore gamer and i bought the 911 with the rennsport wheel stand and i regret spending $480 on this system, i wish i went the cheaper route and got the g25, its about $130 cheaper and honestly its probably just as good, it doesnt vibrate and the shifter sucks but you can modifty the shifter now.
anyways i would go G25 if i had to do it over, soley based on price, and the love for which everyone has for it.
plus my 911, is the worst table mounted wheel ever, it moves all over the place (hence the rennsport wheelstand) and the buttons shake so much, with full vibration, the buttons clatter and it sounds like they cost 2 cents to make....
hope this helps.