I switched from the Kickr to the H3 because I was having significant accuracy problems with my Kickr. It was out of warranty, and I was offered to swap it for a refurb unit for $300 (or maybe $350), which I did not want to do.
Here is an example of what I was seeing on the Kickr:
Other than the accuracy I have been happy with the kickr (gen2, 2016 I think - first one with the handle). Hopefully the H3 will last longer 
I was having these problems during the late summer, in a hot garage. The kickr seemed to get more accurate when the weather cooled down, so it could be temperature related, but at that point it had left my ‘circle of trust’, and I had decided to get a new trainer. I went with the H3 as it has been generally well reviewed, and the ERG mode was reported to be very smooth. (And it is very smooth - I like it a lot in ERG mode.) I timed my purchase to line up with the holiday deals that seem to happen every year, so I got a very good deal on it as well. If the H3 was not on sale I may have considered something else if it was a good enough deal.
November/December is the time to buy a trainer based on these sales - you can pretty much count on at least 20% off at various retailers. The H3 was 25% off at REI and others, and I managed to get it at 40% off! (stacking discounts that maybe weren’t meant to be stackable, but clever training honored it.)