This is more or less the exact setup I'm using (Ubiquiti AP and RB750). I've only had it for a few months but neither have required rebooting once they were set up and the performance is good enough to make my 150 Mbps connection the bottleneck.

I also enjoy the level of control that comes with having separate devices for cable modem / router / wifi AP, for example being able to ssh into the router to configure things like port forwarding.