I rather like the wheel the way it is now for 2 reasons:
1. I like that, despite the fact that I choose what I want to say, I still don't know the exact words. It makes listening to the dialogue more fun, IMO. Otherwise, I might get bored by Shepard's lines after a while.
2. I am a fairly slow reader. The fact that the ME wheel only had 3 word choices meant that I could read all the options and choose, pretty much in the time it took the other person to finish their sentence (note that the wheel usually pops up BEFORE the other one is finished speaking). The gives the dialogue in ME a very nice flow, just like in a movie. If I saw the line on the screen, I'd probably feel obligated to read it (and the devs would feel less obligated to word the short version concisely). That would take enough time to give the dialogues a lot pause, which would seem weird and definitely destroy the flow that the ME games have achieved for their dialogue with the wheel). IIRC, Casey Hudson even mentioned in a very old interview (like 2007 or something) that this flow was one of their major design goals when coming up with the wheel.
Besides, in the entire trilogy and hundreds of hours of dialogue, I can only remember maybe 3 occasions max where I misunderstood the wheel. That's actually quite remarkable, I think. So as far as I am concerned, I'll go with "if it ain't broke, don't ix it".