I have no experience with the Elite Qubo, so cannot offer any comparisons. I have both a Kickr and a Tacx Vortex (in two different places).
In general, I’ve been happy with the Vortex. It works well with Zwift, easily and quickly responding to grade changes, etc.; however, it’s no match for the Kickr. The primary difference (other than the obvious wheel-off design of the Kickr) is that the Kickr has a true strain gauge power meter that is consistent and accurate to with in a couple percent compared the Quarq power meter on my bike.
The Vortex is different in that it calculates and transmits power based upon it’s known internal resistance curves and wheel speed. In essence, it is doing internally pretty much what Zwift is doing online to calculate power with a standard “dumb” trainer.
The power readings are very dependent upon tire pressure, temperature, trainer roller pressure against the tire, etc. I can fiddle with roller pressure, etc. to get it to eventually come close to the Quarq on the bike, but a good warm up to bring the trainer and tire up to temperature is necessary before the data starts to settle in.
In summary, the Vortex will give you the Smart Trainer resistance control in Zwift, through the Tacx app etc. but I think the power data is variable and not necessarily repeatable unless you are diligent with tire pressure, roller pressure, warmup etc… I don’t know what trainers beyond the Kickr (not the Snap) & Tacx Neo have true strain gauge power meters, but that’s the way to go if you want accuracy and can find one that’s affordable.
My 2 cents…