I'd say that a Thumb almost falls into 'Marmite' bass territory. Some folks love them; others not so much. In my time I've owned fourteen Warwick basses and moved all of them on except the Thumb neck-through fiver. It's a heavy beast, but with a wide, suede-backed strap, neck dive is much reduced, although a full hour's set with one, leaves you feeling like Quasimodo at times. The sound - mine is a two-band - is certainly 'burpy' and no other bass I own can get near to that Warwick voice. I'd also say in response to your comment about a Streamer, that these do not really sound anything like a Thumb, contrary to the video, and they are much 'easier' on the shoulder. See if you can find one near you and give it a go: it's the only way you'll ever know if you'll gel.
Best of luck with the search.