We are a WISP and we bought a lot of RB-433AH and RB-433GL (during the time) that serve as access points throughout the network.
It would be interesting to change the protocol to AC but unfortunately the radio-slot is MiniPiciExpress while the 433AH has the normal MiniPCI slot
I am aware that the miniPCI slot is slower but for the use that I do (20Mhz channels) could go.
Do you know if is planned a AC-radio with normal miniPCI slot or some sort of adapter (obviously at an economical price)?
IMHO these devices will be capable enough to provide 802.11n speeds for years to come. And having ac just for the sake of having ac is not that useful.
You mean that the 433AH and 433GL are not sufficiently powerful to handle the AC protocol?
there are certain speed requirements for ac when ran at maximum speeds. And there are certain speeds that PCI bus can deliver. It would be possible to get miniPCI ac card however, it would use up all the PCI bus if used at maximum speeds. So, 1 card per board.
In my case it would be fine !! 
I always use a single radio per Routerboard
So if you are going to produce an adapter keep me informed !!
I’d hate to trashing all these RouterBOARDs to connect new customers in AC protocol
Do you think that this adapter http://amfeltec.com/products/flexible-minipci-to-minipci-express-adapter/ can work with one miniPCI-e 802.11ac wifi card in routerboard RB433GL?