I play it almost everyday but not for long. Also I am involved in a nice community who does weekly racing so I do all the training and all.
But the problem in this GT os the career mode and its lack of contect. I mean how is it possible for a game which has so many cars and tracks, day/night cycle with rain, to be so boring.. Their AI is so weak, one of the biggest reason, but the real reason may be that there are way too less races in career, and licence is now a joke. Befire it used to be very challenging challenges with many many challenges in only one license (Im mentioning GT4 of course), but now its just so easy that I have no fun with this game anymore.
The problem: There are so many content, cars and tracks, but PD has done the worst career mode with it, with stupid AI.
How to solve it: Make a competitive AI and.. way more races by classes! There are only 5 races for GT500, one for GT300, one for GT3... I mean why don't they do something better with it like a special mode for GT3 where you have tons of races, a special one for Nascar and all other things...
Also B Spec and endurance are missing, eith track creator, quick match, Community options... And if you want my honest opinion, these elements won't fix the game either with the career content we have in GT6. What we need is a strong new GT with many many interesting races, like older GT where getting fast cars wasn't so easy and fast, where so many different kind of races. And one of the most important issue: A good AI.