Well i gotta say i've changed my opinion after playing for more, than 2 - 3 days.
Sadly, but this is 1st "normal" GT (GTPSP and all Prologues/Concepts/etc doesnt counts) where i don't have anything fun to do after like a 100 hours of gameplay, which took me about a month.
A-Spec (and everything where you need to actually play):
Special events are done mostly, licenses too, a-spec done everything, except FGT and endurance races. Will do FGT and some early endurances in some future tho, but won't even try any of 9 hours + ones.
Why i won't bother with 100%? Because 24 hour races are just a joke, no one driving 24 hours alone in the real life, so why the "real" driving sim is expecting me to do that? So i won't bother with getting the last few golds in licenses or special events, since i won't be able to get 100% anyway.
There's just nothing to do, 45 "normal" events in A-Spec, average races in each event is 3. Average race has 5 laps. Average race is easy as i don't know what. The only hard (by hard i mean it was actually a small challenge and (or) i didn't won from 1st try and with 1st car i've tried and (or) i had to get some better car than i had) that i can remember are: historic cup, some championship with "dream cars" like Mazda 797B etc and even tho i didn't tried it yet, i'll add FGT championship too.
That's it, everything else was too easy, i don't even think i've tuned any car to win those races. Gotta say tho, that are those seasonal events part 2 was fun to do (except nascar, it was easy and not fun, because nascar on the ring... that's just not right -.- ).
B-Spec:
It's a joke. It's everything, but not a game. Some may say that you need to give commands (wow, whole 4) to your driver, but he will win without that too (people who are grinding 24h endurance events in b-spec while they are sleeping/working have proved it).
Why would i watch how cloned AIs with different names (including Bob ) are racing, when i can actually play on PS3? You know, i don't have limitless time to play and when i get a few free hours that i can spend on a game, i actually want to play the game (GT5 or any other game, that's doesnt matter).
Maybe i would done it after some time, but it doesn't even has a 2x/4x rewind function. Yeah, it's so fun to watch... especially since it has 2x (and i heard that later it will be 3x, not sure tho) ammount of laps for the every race.
Online:
The ammount of idiots and rams, who thinks that is another NFS game is just too high. And i don't like playing to the racing games online anyway, that maybe a nice addition to a GT game if you love it, but that's not why me (and i think that the most of people who bought it) got the game. I got it for GT mode obviously.
Collecting cars and grinding:
Because there's such a low ammount of races (even with b-spec ones) there's no need to get most of the cars at all. Especially that goes to the old cars. Yeah, you can buy it, but will you use it anywhere (maybe online tho) ?
The 2nd problem is.. you can win a car only once. That leaves us with grinding the same events (ovals or endurance ones for some people).
GT4 had a better system i think. Of course there were an ultimate grinding event with max money for min time, but still, if you've decided to do some long and hard championship, then you would have got some good money in the end.
In GT5 if you wanna grind, then... read above. If you'll want to re-do some early race or even dream cars championship (or how it's called... lvl 24 one), you'll get nothing. Early races is a like 10k credits and 1k exp, lvl 24 one gives more, but if compare it to oval grinding, it's still not good. So no bonuses for doing hard races.
And there's no point of leveling after lvl 30, unless you want to race in 24hr races. I would grind (not so fast, because i don't have enough time, but still) if i had something to grind for. Now it's all the same, 30, 35, 39, just digits.
Final thoughts...
I still love GT5 and i even don't care about such things as standard cars or bad shadows or lack of <insert car model here>. I'm not that hardcore gamer or car lover, so that's fine, but i just don't know what to do in GT5 now.
Don't really remember how many total races were in GT4, but i got a feeling like a 10 times more and i could actually play to each one (only used b-spec there for the long endurance ones, since it had rewind button).
I hope PD will keep adding 5 new events every now and then, but even in 1 year there still won't be that much races as it were in GT4 by default. Let's not forget about those people who don't have internet on PS3 (or just internet at all), they will stuck with default events, not so nice...
Also i would like to hope that GT6 will be released on PS3, because if not, then 90% of the new 4 - 6 yeard development cycle will be spent on graphical/physical engines and new car models, instead of the game content.
Oh and it took about 1 year to reach the point " what to do now" in GT4, 12x faster in GT5.
So 3 days ago i've tried that birthday glitch for the 1st time ever. It'll keep me busy for the 2 - 3 more days, but that's not that fun, i would rather won those cars... and there's no place to use them. >.<
So yeah, i'm a bit disappointed with GT5, but not that much so i would say that the whole series just died tho. =)