I recently upgraded from Asus to Apple, throughput went up, availability went up!
(hanging off a long distance 802.11A/WiMax mountain top ISP-company in the alps)
this shiny 2013 Extreme does do AC quite well, limit of about 50 clients, and I was able to find it refurb - Apple are about to drop making new ones, according to rumors. AMZN currently has them for £159.
Strangely, my ISP (often) cut my RT-AC56U off as it was pinging for NTP 'too-much' in their opinion, the previous Asus RT-N16 was perfect - but was taken out by the EMP of lightning hitting something in the garden.