Honestly, the 1008 and 3008 are two completely different beasts.
Although the 1008 is a nice machine, the 3008 is higher-end.
First of all, in the video processing department, the upgraded HQV Reon VX chip on the 3008 is much better than the Faroudja DCDi Cinema chip found on the 1008. If you listen to alot of 1080i or lower content (DVDs, cable/sat, etc) then you might want to invest in that better processing power.
In the audio department, there's an even bigger difference between both receivers, the main one being THX certification.
Considering you say you have a small room, than the 1008 should be sufficient (Select2 Plus rating).
In a room 3,000 cubic feet or more, I would say for sure to grab the 3008 hands down.
On the 3008, you get less THD (harmonic distorsion) than on the 1008 (0.08% vs 0.05%) meaning cleaner signals.
Finally, another great feature on the 3008 is the addition of the all-new MultEQ XT32 speaker calibration system, where the 1008 "only" comes with MultEQ XT (still awesome though!).
So basically it boils down to just how much those extra goodies are worth to your eyes.
At low volume, both receivers should pretty much output an identical sound quality in my opinion.
Anyone you choose will be a great buy!