OK, I've had several high-end ASUS routers and I know that your ASUS router is probably not stable and needs to be restarted all the time. At very least, Unifi is a huge step up from that and it will easily run at max performance for 3+ months at a time without a reboot.
I haven't experienced any instability with personal routers to be honest.
A ton of proprietary software and the externalization of support on a third party.