I rate the Ultramax high, based on quality, as well as performance.
It's also an easy install, and comes with a nice seat.
When I was growing up, my father had a Chevy Nova with a 305 V8.
Plenty of power, no traction in the wet, (I do live in the Seattle area and do a fair share of skiing)
I wound up buying something that did better in the snow.
Right now I have a Mitsubishi Outlander all wheel drive, allow wheels, ABS brakes, sun roof, with a 4 cylinder engine. Not a lot of power, I can't lay a patch of rubber with the thing, but runs smoothly up the passes in the Winter.
I sell all the brands of toilets, and this model quietly gets me plenty of repeat sales.