WPA2 Enterprise without a Client-End Certificate

This question is practically identical to this question, but the difference being that the authentication server is freeRADIUS on Ubuntu and the access-points are DD-WRT.

Additionally, I would like to know if there is any risk to disabling TTLS (which from what I understand the part of the authentication process that requires the certificate) or if that is even an option.

I understand now that there is a difference between TLS and TTLS. I want to use TTLS, since it does not require client configuration. I have assigned the answer to the post below because it helped come to this realization and I have edited the title to better reflect his conclusion.

Solution 1:

Skipping the marketing crap, "WPA2 Personal" uses the hash of a passphrase to secure the session key exchange and establish access to the wireless network. "WPA2 Enterprise" uses 802.1x EAP to secure the exchange. Technically the WiFi hardware could support any EAP Method, but only EAP-TLS (Certificates) was required for the WiFi certification (it's been changed now, but was this way for a while), so it's commonly the only one well supported. PEAP, EAP-TTLS, and EAP-SIM are now also supported, though setting them up is mostly just as bad.