I, for one, loved the first Sonic Adventure. It seems to catch a lot of flak these days, but remember that it got excellent reviews in its time.
That said, I can understand why fans of old school Sonic did not like the new direction of the series, even if it was quite well executed, and I readily admit that Sonic Adventure 2, Heores, etc. were less fun. I have high hopes for this new title - the change in genre doesn't bother me at all.
"There is nothing new under the sun, but there are lots of old things we don't know yet." -Ambrose Bierce