low end floorstander or high end bookshelf?

i'm currently running a pair of b&w 683 floorstanders with a large velodyne hgs-18 sub. would a better quality bookshelf like a b&w 805 diamond with the same sub be an upgrade? i've heard that even with a sub, the bookshelf doesnt sound quite as "full" as a floorstander with the sub.

im about 50/50 music and home theater. i'm more critical of the music tho. thanks.
Does it have to be B&W?
You may find a good compromise with high-quality floor standers at the price of the 805.
I agree that it is a matter of Quality vs Quantity, I would always go with quality.

At one time I had a large room (24x13) and had my two Rel Strata's hooked up to LS3/5a's, even though I had my main speakers which were Kef Reference 2 (excellent speakers in their own right), it was musical bliss when it came to the Ls3/5a's!

Would you lose anything without that dedicated midrange driver in the 683? Or can single drivers in bookshelf speakers sound pretty darn close?