floorstanders or bookshelf for HT fronts? HELP

Just a quick question. I finally have the chance to seperate my HT and 2 channel, but need to pick up some new fronts. Currently have Paradigm studio center and studio 20's for the rears. Since i'll be using a sub, what advantages do floorstanders have over bookshelves like using a pair of studio 20's up front? When setting up the speakers, I run the fronts as small. When floorstanders are ran as small and the sub is crossed over at say 80 to 100hz, doesn't this basicly reduce floorstaders to bookshelves as far as output and sound is concearned, since the load of the bass is being handled by the sub? If i'm thinking backwards, please help. If i'm better off going with studio 60's that's fine, i'm just trying to learn from all of you that have traveled this road before. THANKS Chris.
I hafta agree with you on all points. I've a Vienna arrangement for my HT (Mozart mains, Maestro center and Waltz rears - using Rel Strata Sub). I chose a floorstander only because I thought we would use it for music when entertaining - proven to be only about 3 times a year, and for background music only. An equivalent system could have been installed for less had I not been a audio geek (and loved the look and sound of the Viennas).
One thought... I haven't rented/purchased any DVD Music videos or SACDs (the HT is the only system that can play them). If there is a different speaker setting which would be more hi-fi than the video settings when spinning these disks then floorstanders may still be applicable.
With your two channel system now out of the picture, get another pair of 20's for the fronts. If you feel that you do want to go with large front speakers then you should get the Outlaw audio ICBM bass management unit ($300 new). This unit will let you cross over the front or for that matter any other channel in your system at other points besides 80-100hz. for better system tweak.