I know what you mean - you want more classifiers by content, like the P2P classifiers in MikroTik.
But the question is how important is it to be able to classify HTTP traffic running on non-standard ports?
This mostly will be special web applications which could be better classified by other means?!
I also vote for content filtering. That missing feauture had strong infulence on my clients decision to use something else and not MT in several occasions.