Dissapointed with my new speakers

So a couple of weeks ago I replaced my 2 year old Klipsch RB25 bookshelves with a pair of B&W DM603 S2 floorstanders. When I first auditioned them I fell in love with their resolution and clarity however having lived with them for two weeks now, I am very dissapointed in the low-end and to a much lesser extent, the midrange.

On most songs, the bottom end seems very lacking compared to the Klipsch bookshelves and simply pales in comparison to the Klipsch RF82s we have in the living room. In addition the mid-range seems a little over emphasized. I can probably get used to the mid-range however, the lack of low end impact I probably couldn't get used to. I was thinking about adding a subwoofer but a half-decent one would start around $250 and go up from there and the speakers themselves are worth around $450-500. This got me thinking, maybe I should just switch to a different pair of speakers instead of trying to make the current system sound better. What do you guys suggest?

P.S.-I'm in Hawai'i so while I'm open to used speakers, shipping here will usually run about $250+ for floorstanders so I'd only have about $500 for the speakers.
I had two pair of the silver series. One pair was the 5's (gold cap in the middle of the two 5 1/4" drivers). The later pair was silver 8's I believe (2 x 6 1/2" drivers plus the same gold metallic tweeter). They were my first ventures into better speakers, but they were brutal for digital music in my setup. I'm not trying to make them out to be crap, they were nice for what they were in a home theater setup for someone that only occasionally listens to music.

I guess a lot of people get spooked due to it being easier to sell amps, source gear, etc. than speakers, plus the limited ability to demo stuff that's not in your town. Bottom line though, I'd say just as much or more attention should be payed to getting the speakers right than anything else from what I've learned.
As for what I was driving the MAs with - it wasn't super great gear, but not bad either. Originally it was a Denon receiver. Then an Outlaw amp and pre/pro. Then I believe I had them paired with a Musical Fidelity A308 integrated for a time at which point I traded them in.

I moved up to Quad 22L2's which were a big improvement. I can say that now having just sold them so I don't look like I'm pitching a product for my benefit.

Moved onto Living Voice IBX-R2s now after just selling my Quads.

At the $2k and below price point, it's hard to beat the Quad L2 series. Vandersteen I hear brought up often, but you have to be a fan of their appearance to go for them.

Gibbon 8's are supposedly fantastic for what they are and can be found used in the $2k range. I tried the Super 8's for a week, but they're a bit neutral and out of the price point.

Great answers! Sounds like you gave the MA's a chance to shine and they couldn't for you.

I like the Gibbon 8's. Better than the Quads - but not by that much. The Quads are a REAL STEAL.