We have a Class B and an SUV/small trailer rig, so I can speak to both.
Biggest adjustment when the Class B came along was the ride and coach soundtrack (squeaks and rattles from the appliances, cabinets, and their contents). The Class B is reasonably smooth and quiet on good roads (with careful packing) but deteriorates quickly on bad roads. It is a heavy duty truck and everything you bring is inside the same space with you.
I rarely hear such good things about RV cabinetry (high-end custom builds excepted). Part of it could be you don't hear what goes on in the trailer when you're moving, but I suspect you may be disappointed in the build quality of the mass market units you're considering, with Coachman and Winnebago generally considered a cut above Thor. Pleasure-Way has a good reputation. My Roadtrek isn't terrible, but I've had some issues with cabinets separating and an ongoing assortment of annoying sounds I haven't been able to track down. For something well made but generally a bit more utilitarian, consider a used Sportsmobile conversion. Hard to find.
A Class B is convenient when you're moving daily and traveling a lot of miles, but if I were in your place I'd be inclined keep the T@B (unless it’s already sold; couldn’t tell for sure) and spend the money on a tow vehicle upgrade. My choice would be a used Lexus GX, with more ground clearance and 4WD capability, but there are domestic options as well. Raise the trailer suspension as needed.
At the least, test drive a few used Class B's and decide whether you're okay with the trade-offs. There's a bit of a cut-point around 20' in length, beyond which you get more livability at the expense of maneuverability and parking. Ours is right at 20', but its long wheelbase makes for a massive turning radius compared to our SUV/trailer combo.
Just one person's opinion (subject to change without notice) and probably the minority view on a Class B-specific forum.