I have a 2021 Workmaster 40. It's a nice tractor but it takes some getting used to, but I suppose they all do. Compared to the TC26 DA it replaced, it's obviously more powerful and has 3 ranges,something I longed for with the 26 hp machine. The LS Workmaster has some features that are better than the TC 26DA. The smaller machine had a tiny fuel filter that was hard to keep from clogging in the winter, even with additive. The one on this machine is much bigger and has a drain to get the water out rather than a bowl you have to remove.
I think you would find the controls on the Boomer a bit more ergonomic. The TC 26DA had the levers on the fenders. They were visible and easy to get out. On the Workmaster 40 the controls for the 4 wheel drive and the front/rear PTOs are sort of under the seat. The 4 wheel drive lever is not visible, and I have to reach down to check if I left it in or out of 4 wheel drive.
The Boomer, I believe, like my TC26DA has a loader that curls and raises/lowers simultaneously. The Workmaster only does one or the other at a time. No biggie, but it's nicer to have the dual action. The Workmaster is a much less quiet machine than the TC26 was, some rattles, which I thought were coming from the 3 pt. linkage, but actually came from the ROPs. Some plastic wedges quieted them down. The little boomer had a tiny toolbox, and the Workmaster has none.. Workmaster has a metal floor, Boomers have rubber mat. I got a horse mat from TSC and cut it to fit my Workmaster. It cuts down on the noise a little.
Used boomers, like my TC26DA have one very annoying feature: the brake is on the right side of the tractor and unless you have two right feet, you can't use the brake to steer and the pedal to move at the same time, defeating the purpose of having a left/right brake pedal. It's a small, but ridiculous thing. The Workmaster, and I think, the newer Boomers have the brake on the left, and no longer a pedal clutch.
The dealer here basically doesn't sell Boomers except cab models, saying the demand for them at higher prices than somewhat (not totally) comparable Boomers isn't there.
Be aware that with the Workmaster 40 there is an apparent error in the Tractordata site as to the loader capacity. My owner's manual says 880 pounds and they say about 1100 to full height. The Boomers have significantly stronger loaders, are somewhat larger and heavier too. The Boomer is supposed to be a more refined and heavier duty machine.
I think the next step up from a Workmaster 40 is a 50, and it's a much larger, heavier, more expensive machine.