Hi Ian.I see Wayne got the question on the CD flares.
Your second question was whether the 7 Pi's would be like the 4's if they were pointed right at you. The 7's are 1) corner horns and 2) quite a bit larger than the 4's. These 2 points make for a speaker with a lot of bass.
The down side to corner horns is you need open corners in a fair sized room. The 4's don't need corners and don't take so much space.
Good luck with whatever you choose. One thing you can be sure of. There is lots of playing you can do.
Grant.