FWIW, I just bought my first non-Airport router for several years this year. I did a lot of reading, & ended up getting an Asus one. It wasn't the cheapest option, but then neither were my older Airports. It's actually way more configurable than the Airport it's replaced, & will support VPN connections & all sorts of port & protocol-based filtering. It's really nice, & really quite simple & flexible right out of the box.
I can also hang a USB3 hard drive off it & it'll appear as a network share, so the thing'll work as a NAS too, so it's probably possible to set it up for Time Machine backups (I've never looked into this in detail, though, as I have a QNAP NAS that already does that).
PS: I have no affiliation with Asus, other than I've been really impressed with their hardware+firmware so far for my own personal use.