I was in your same dilema just recently. I ended up going with the Imagine T for my front setup. The Imagine T's were simply cleaner, more detailed, and look beautiful. The Image T6 were nice but if you have the cash i would spring for the Imagine setup.
The Imagine T's do not have quite the bass, but i have rythmik subs now and the blend is just awesome. Again, very clean, crisp, sound, and the subs do the bass in a similar fashion. The Imagine T's will produce some bass dont get me wrong, but it muddies their sound to me. I have the top port plugged so the mids are nice and clean and again, lower end is handled by the sub. The imaging is very good, the upper end crisp and clean. The Image T6's sounded a little harsh so to speak on the upper end....not terrible but when you run them side by side you can tell. I was able to get both in the same room, running on the same setup using the same demo songs.
So, choose what is important. But if you have to save a little more to get them, do it. I am glad i did. I got a super deal on mine. Check around, i think saturday audio has some b stock (not all that sure what that means) that you can get a pretty good deal on.