I wanted to like Soma--they've got a good selection of mattresses--but I found their customer service once I bought one to be pretty terrible.
A year ago, I purchased a mattress that felt great in the showroom but that I ended up not finding that comfortable to sleep on--which happens, I know. From pretty much that point on, though, I had to chase the store to get any help, and eventually I couldn't get them to return my emails or calls at all. They seemed knowledgable and capable the few times they belatedly got back to me, but, in general, reluctant or unwilling to do much of anything once they'd made the sale.
I suppose they didn't have to do anything, given that I'd stupidly bought a mattress I couldn't return. (I wouldn't have, but a few of my friends loved mattresses they'd bought there.) But that's far less than I'd expect, let alone hope for, from a place I'd just spent a few thousand dollars at.