I have had Infinity for years using HH2 (the curved one with straight edges) and has worked fine. 100% wireless connections to all the devices I have ever tried. Currently using WPA/WPA2 on channel 11.
Wireless is connected to Wii, Xbox, iPad Mini's, iPhones (3 & 5), Android phones, Windows phones, all fine no issues, all showing connected on the "Home Network Page". There are still DHCP leases available. I maintain my companies IT infrastructure so setting up HH was easy compared to some of the kit I normally use.
However I bought my wife an iPad air for her "multiple of 10 birthday" and I have not been able to get it to connect to the HH. It can see the wireless network, enter password, but ends up with a self assigned network address and iPad complaining it can't get access to the Internet.
I have tried ipad "forget network setting", "reset network connections" and "reset completely" no difference. Removed all security off wireless, no difference.
I reset the iPad, bought it into work, went through setup and it connected first time to our work "hidden" WPA2 network (from a Draytek router), so wireless works. Took it home, tried to connect to home wireless network, same error.
Might borrow our works "spare" HH3 infinity router and try that at home, unless someone has other suggestions ?