I haven't used it but have been reading around various devices for the best part of a year and I really like the Banana Pi BPi-R4. It's not perfect, but it's a decent device. I would use it with a seperate AP though.
I just did this. I installed a banana pi r4 as my main router with no wifi, and a couple of separate APs. I bought some Extreme Networks APs on ebay for USD$15 each, already flashed with openwrt.
I used the YouTube tutorials by OneMarcFifty to set up vlans for alternate SSIDs. Works great!