I am not trying to take this thread from you... honestly

1) Okay guys, I know a lot of you have the Pioneers 8x7 (or 8x9, or 8x6.. dunno the right size). I have the "Premium Sound", whcih i dunno if has better speakers, I do know I have a Ford Amp that i don't use, but the thing is: would I have better sound going from the For Premium Sound Speakers to a Pioneer speakers ??? I thought the ford Premium speakers were the BOOM....really... I love them,,, but since a lot of people are saying that they are worthless I wonder how much better my sound experience would get.
2) Now that I am stereo (long story) I can isolate the rear speakers. I noticed that THERE IS NO MID / high frequency coming out of them. Is that normal or something is wrong ??? they are acting like a 'wanna-be-subwoofer".... i just thought that was strange. Should I buy better speakers for the rear seats ????
Thanks !