Keep in mind that basses are made of wood, so their weight fluctuates rather a lot. (This is one reason I like Sweetwater; they post weights for each serial number of each instrument.) My SR500 was just 8 lb 4 oz with the stock tuners, for example. That said, the BTB33 is on average heavier than the SR500 or SR650 you mentioned. The body is bigger and less rounded. Mine was 8 lb 13 oz with the stock tuners. That said, I find that balance is at least as important as total weight. The BTBs, including the 33, are very well balanced, even with the stock tuners. The GB350s I have on it aren't really necessary.
Thanks for the response. I totally agree balance is a huge factor in comfort. I play a lot of solo bass lately (tapping Stu hamm type stuff, got burnt out on the whole band dynamic) and this bass looks very tempting although part of me wonders is this just a manifestation of the novelty aspect engrained in our DNA (grass is always greener).
Thanks.