I love it so far! I have done 4 Zwift rides, And I have to admit i have never had such a hard workout on the bike before! The hills are really killer on the smart resistance. I have done one 500m climb and another 650m climb on zwift. I was almost dying at the very top. If anything the smart trainer was too strong on the 17% grade hill. I literally could not pedal it sitting down, I had to stand for about 15 minutes constantly pedaling. I definitely think I have gotten way stronger in 4 already than I would have in 10 rides outside.
It is such a joy not to have to spend 30 minutes getting dressed and undressed from a winter cycle.