I have a quite long apartment with reception problems in some rooms, and was planning to buy a mesh system (like the TP-Link Deco M9 Plus or similar) to replace my aging range extender (which is stuck on 802.11n now that I have a 802.11ac router).

I'm more of a software guy, don't know that much about hardware and networking, so can any expert on these things give an opinion as to whether this is a bad moment to buy it? Would it be better to wait for 802.11ax/6 to arrive? When can we expect to find hardware (such as mesh kits) reliably supporting the new standard?