There are a few different lines within the type x line. There are the regular type x's then there are the flaship and the absolut top of the ladder is the f1. I have the 5 1/4s and jsut had to cut the back out of the plastic "frame" as described and it fit fine. They also have have been/ will be redesigned a bit soon with a smaller x over and different tweeter. Supposed all will get the f1 tweet in some form. Thats what ive herd. I had my xovers which are big, in the doors for a bit but i messed with it so much i moved it to the trunk where it was easier to get at. Quality is really good on these speakers. The mid, im pretty sure is a vifa design, which is a well know company from denmark and is heavy and looks very well built. Tweeter is a bit harsh for my taste. I have eq'd them a bit. This could be due to speaker placement also. I found mine on ebay for 200.
I herd the x's a/b with the type r's and no contest. X's blew them away. I would suggest no rears and jsut the type x fronts. Ive been sastified with this and think having r's in the rear will degrade the sound. I don't like rear fill anyways though.