WPA2-AES (without mixed, without TKIP, as you've shown in your screenshot) is still quite secure. WPA is nothing like WEP (which might as well just be open with today's technology). There's been some attacks against WPA, but WPA2 is basically only vulnerable to brute force attacking of the passphrase, which is more of a problem with preshared key and probably lesser of an issue with Enterprise as you shown.
It's complicated (tm). WPA2 is based off AES128, but the key derivation is per-session and sourced from other information together with nonces. It's hard to find a good diagram, but this student actually did a great job at explaining the key derivation:
I would not be concerned about the key length being a security issue personally, but of course I'm not sure what kind of attack vectors you were concerned about preventing. It's far more likely that weak user credentials are going to pose more of a problem than brute forcing the encryption scheme.