Definitely go with a system that keeps things local. I didn't do much research beyond the Unifi stuff because I already owned some Unifi network gear (and ended up replacing my non-Ubiquiti AP with a nanoHD). So it made sense for me to buy the cloud key gen2 + a few cameras. I'm very happy with it - it's almost unbelievably fast when connecting to the cloud key remotely. As in watching your stream or a recording within 5 seconds of opening the app. Arlo takes 10-30 seconds to do the same.
Cameras seem legit, and are can be pretty cheap ($75+). Either way, I would have gone local and I'm kind of surprised to see anyone here suggesting cloud-based solutions.