yes, we'll optimize for speed soon (but we hope to optimize at the right time). bedroom and dining room are next on the list. getting visitors is indeed the big challenge. SEO, viral/social, and SEM (in that order) are what we'll focus on. would love feedback in this area as well.
yes - account creation lets you save rooms that you've created (we have people who have spent hours putting together different room combinations) but you're right about the high hurdle and we'll shortly be releasing a version that you can use all the way through without signing up.
We recently released a new version of the quiz, and looks like we had an IE7 bug which we'll fix right away. BTW - 55% of Sproost visitors have been FF, only 25% have been IE7/6.
using FF 3.0.5 here. I get stuck on the 2nd step of the quiz. The spinner spins forever. However the funny thing is it appears to work fine in IE 8.0.6
