[Sonic and Sega RT] Ok so I could tell it was a good game but felt that it was a bit plain...until the jet set radio drift challenge ! big smile on my face, nice graphics with the extra things on the screen and great stage, also decent music mix.
Framerate dips aren't annoying, for the most part it's not an issue, doubt people will notice much. One stage (as a previous poster mentioned) has a noticeable dip (samba) but it's no where near modnation bad (so far) at all. It's good.
Will play some online after I unlock some stages and post back.
Framerate isn't what I hoped though tbh (aka not rock solid - doesn't dip that much and it's perfectly playable but come on sega/sumo :/ ) - and the graphics aren't anything to shout about so not really much of an excuse. Not the best performing or looking game by any means but not bad at all either. And fun if you like sega/karting. Some really cool mechanics in this.
Showing the game logo instead of a decent animation when you go offtrack is a little bit tacky.
You can barrel roll without doing a (right stick) trick which is quite nice since criterion disabled it with NFS:MW - going over a ramp with half your vehicle.
Quite sure you will love it

I'm just extra sour with framerate-stuff (which tbh is actually fine) and was hoping sega would razzle and dazzle me like with JSR
haha
just as I say that.. [damn can't upload screen atm, will do in a bit..going to play some more - but some very cool events/levels] - some levels are actually amazing/fantastic, a few of the earlier ones less so
Good loading times as well.
Challenging difficulty - medium feels very good for first play-through.
Also feels like they tribute some of Mario 64 in this game in sega's own way - the ship crossing in the donkey kong level over the bridge. rainbow road. the cars from that traffic level. Really nice touches.
Make sure to change to control type B - accelerate with X and drift with R (instead of the other way round). Don't do this, it makes it harder to do stunts.