Dont know about the RB1100AHx2, but I have the RB800@1000 and can its about 3-5% with 12mbit over a pptp link, firewalled though. I dont think you will have any issue with the client load at all( i dont use hotspot). I also have pcc and wifi on the RB800 and top load during the year is 15%. The RB800@1000 is about 48% the performance of a rb1100ahx2
We have a 1100AH servicing about 100 clients passing around 20mbit/s of traffic, kicking happy at avg. 8% cpu with full firewall, NAT etc.
Its not the number of clients that matters, its the amount of traffic, firewalling and QoS and other features combined with this ammount of traffic that causes load.
I have one location with 17Mbps internet link, PCC, QoS, netflow (no NAT, L7 or SMTP) and RB1100AH peaks at about 35%. I don’t think it would handle 4x more traffic.
as you can see from user reports it depends on specific configuration. also, take into account that behaviour changes on higher loads, for example packet polling kicks in, instead of having interrupt on each packet.
I have one running with simple queues, user manager (with disabled accounting), firewall, dynamic mangle rules, bridge filters and around 300-350 pppoe wisp users.