In regards to the Type-X's, i just installed a set today.
I started off the day by using 6x8 adapters to get them to fit, and then mounting the tweeters up on the dash in the corners with the angle/flush mount. Personally, i think a system sounds MUCH better with tweeters up their. Anyhow, without tuning anything, i could tell the speakers were much "smoother" then my type-R's. I spent the day dynamatting the crap out of each door, and the labor was completely worth it. I noticed much more mid's then before. The crossovers that come with the X's are insane, they are bi-ampable for one, but you can change the phase depending on the distance between the woofer and tweeter, but don't worry the directions tell you what settings to use for the distance it is. Also, like most others, you can change the tweeter to like +3db and down to -6db. To get an idea of my likings....i like to listen to my music loud, stuff from Journey, to the eagles, to akon, to greenday, pretty much EVERYTHING that has a good beat, and a great voice. I don't like to blair my music if it sounds bad, i just totally dig feeling the concert-like experience. To be honest, i haven't heard THAT many installs. I have heard, and currently have, an insane home-theatre system, so i DO know what do music should sound like. I'm sure you searched and saw the review as "the x's have a natural sound, not a trembling mid-bass", and honestly, i'm GLAD they do. It's a much more soothing sound, more relaxing to listen to. At first i was surprised, but when you keep turning it up and up and realize their is absolutely no distortion ( correct settings, power ) you just get blown away. I demo'd today to a few buddies, and they seriously just smiled like fruitcakes because it was so ograsmic. Seriously though, if you're like me, and enjoy listening to all types of music with amazing clarity, i think you will NOT be dissapointed in anyway with the X's. I could not be more satisfied with them myself, it was definately a night/day step up from the R's i had. Anyhow, if you have any questions feel free to PM me, since i just spent 2 days straight installing/tuning i may have a few answers for ya.
Cheers,
-Austin