I have the exact same router (with Merlins firmware) and never get any disconnects and I have a lot of devices (mbp, macbook air, macbook, iphones, android tablet and ipad).
Do you live in an area with a lot of RF noise? or with a lot of other Wifi networks? I've stayed for a month in New York last year at a place with a lot of other wifi networks and my Macbooks became much more flaky when connecting to wifi.
Maybe you can try changing the wifi channel?
But I can say that having an internet connection that's not great definitely creates a lot of problem and additional frustration. I was way more frustrated when I stayed that month in New York (for some reason the internet connection had intermittent packet loss), I'm really quite surprised at how bad internet connections are in the US.
A house in suburbia. I can see maybe 5, possibly 10 networks tops, with a good client. I'd categorize that as "not a lot of noise", at least not from other WLANs.
I've tried different channels, but is that suggestion in regards to the signal (which is not a problem for me) or for its effect on reliability of keeping the connection?
No disconnects at all. I don't reboot the router often at all either. In fact I realized I probably should reboot one after realizing some issues with the onboard RAM and the uptime was over 3 months at that point.
I'm in the San Francisco area so you'd think RF noise would be pretty heavily present here. Before this I had the TP-Link AC1200 and I had all the issues you mentioned with that.