I have Shift and GT5. GT5 did not live up to the hype, there are innumerable posts by disgruntled GT4 players (so there's no fanboy bias), and most seem to feel at least a LITTLE shortchanged.
GT5's driving physics and graphics are very nice, but Shift was just so much FUN..! If you having fun automatically makes it an 'arcade' game, then so be it. GT5 could do with a healthy dose of arcade if that is the case!
I really hate to say it, but all Shift needed was GT5's accuracy of driving physics, better wheel FFB implementation (on my DFGT, driving a straight line was a terrible exercise in dampening unrealistically exaggerated wobble), and some increase in size of the Garage, and an online system that allowed bashers and lurkers to be booted, and GT5 would have gone back to the store.
Some of this is promised in Shift 2 Unleashed. If delivered, GT5 is going to have a run for it's money. I NEVER had any need to grind in Shift, upward progress was logical (if a little easy), online was a piece of cake to find fairly matched races, but the bashing was intolerable.
I THOUGHT GT5 was going to be the answer to all my prayers. At the moment, it isn't. Perhaps Kaz has great plans, perhaps he's just counting his money and working on GT6. Who knows? But I honestly, from all the hype, did NOT expect to find myself looking back on Shift with anything but scorn, and I did NOT expect myself looking forward to Shift 2 in any way...
God help me.... I do!