Hey ejschultz, if you can upgrade your doors to a 6.5 you will be much happier with the midbass on the ID>You say you don't want to drive really far just to listen to a set of speakers!
To me thats the best way to judge for yourself whats sounds good to your ears, verse listen to so many different opinions.
If you are looking into the new Alpine -x comps i would at least listen to them before buying.
The older Alpine-x comps where made buy scanspeak & vifa,which are/where really nice.
Im not sure who makes there newer ones,plus i think they have 2 different models out.
I think the the tweeter can get loud, the tweeter sounds more of like the boston pro to me at least.
The lower mid is nice , it can get low, but upper midranrge is kind of harsh when crack them up.
if you decide not to do a rear fill,that will give you more money to add deadener,yes deadener isnt cheap.
Since you are doing a 2way set up, you want to just seal the your doors, add dyna-xorb behind the speaker to help with reflextions.
built your own speaker mount out of MDF.
If you go to homedepot go to the back of the store to where they cut the wood, you can find a scrap bend that has cut up boards from MDF,to birch wood.
I think they sell pieces for like .51-$1.61.
anyways good luck