We will probably need a good Internet connection from our room and both the Marriott and Hilton have high speed Internet, so I think it's between the two.
Yeah. The only hi-speed internet Disney's Grand Californian has is at it's Business Center which is only open from 8am to 5pm daily. In the guestrooms, it's just dial-up.
The Hilton is offering better rates than the Marriott for the convention, but you think the Hilton is actually the better of the two. Any particular reason or is it just generally more apealing?
They are both nice hotels, but I think I'd give the Hilton the edge because of it's better public facilities, IMHO. Better restaurants etc. Also it's slightly closer to Disney, though that would only matter to you if you plan on walking over. And since you say the rate is lower at the Hilton...I'd suggest you go with them.
This is all assuming your convention is at the Anaheim Convention Center?
See updated info on Hi-Speed internet at Disney in post #13 below.