You only bought 4 ultra 4K cameras for the house. I have to say after a few different brands and trying to find something compatible with HomeKit, I think I found a good answer. The house is about 2400 sqm and has plaster walls, so usually wireless signals have a lot of problems going through several walls. So far, the Ultra base station has managed to cross the walls. I tried Arlo 2 and I didn't have much success by going through the walls.
Anyway, if you just want to give a quick review, if you are looking for a decent camera system for your home and want HomeKit compatible then Ultra has been pretty good so far. However, I would like to see different lens options in the future.