Ok for base mileage, not for intervals
This is a simple trainer. Its stable on it's base, the contact wheel is fine and doesn't put any bump or wobble into the ride. But know what you are buying. It's okay for base mileage as you can spin away all day and get in zone 2 workouts a-ok. With no adjustability, I find the resistance level on par with that of being on a flat road minus any wind resistance. And thats the problem. The fan / flywheel only provides a degree of resistance up to roughly 20mph, then from there the progression seems to level off. I can spin out 52x11 to over 45mph during hard intervals. You can adapt and do some intervals ok, but even in 52x11 you cannot mimic hill workouts, and power based intervals are not optimal. You can do plenty of other "intervals" by blasting out high cadence to get your heart rate up, and that has actually helped my on-road riding perceptively.
THE SOUND IS LOUD. I read reviews, saw it was loud, and risked it. This thing is unreasonably loud. You won't hear your tv. You may hear music on a stereo at it's top level. Headphones are a must for musical distraction during rides on this trainer. Your family, if any, will hate it. if you live in an apartment your neighbors will become enemies.