You need Airport Extreme. Time Capsule has been a POS since it's introduction.
Interesting. I have had no connectivity issues with my TC. I had a problem that I think I created and they simply swapped out the old and gave me a new one. Funny thing though, as I live in Finland, I have a North/South American TC. Got the super wide channels that my European AirPort Extreme can not link to, to extend my network. My iPads, MBP's and Mac Mini (linked to Internet via CAT6 cable going to my 200Mbps Cable modem) all connect with no drop in connectivity. All report a 300 Mbps connection in the Network Utility --> Link Speed app.