Attention to detail

I heard the 603S2 ... fantastic rock speakers, but not very subtle. Detail has several forms. One is hearing the smallest sounds, another is imaging.
Based on what I heard you would have to spend more than $1000 new to get the rocking and bass abilities of the 603s with great detail and imaging. Someone above suggested the spendor 3/5 ... with all due respect it's a completely different speaker to the 603, and I suspect anyone who really liked the sound of the 603 would hate the 3/5 unless there was a good subwoofer with it.

So s7horton ... if you like the general sound of the 603, but would like a bit more finess then I'd go a bit higher up the B&W line (e.g. CDM7), but if you'd like an altogether different sound .. more detailed, airy and ethereal then there are many many suggestions.
But, to be honest, the 603s are very enjoyable speakers. you can spend a lot more and get a lot less speaker.

My B&W dealer thinks the 603S3 is godawful! Pretty lumpy bass to me, too. The bargain here is the ungainly-shaped 602S3, by far. For $800 used I bought FAR more natural Spendor SP3/1p, though the B&W will play much louder, deeper, and brighter. Depends what you want. Just stay away from the universally-despised (I just toured Scotland, and ALL the B&W dealers raved about the 601 and 602, and hated the 603...no kidding!).
Maybe it works in your room, though, if the bass integrates in a weird way. Good luck.

The 602s3 is one of the best speakers for the money IMHO but the 603s3 isn't chopped liver! The new 603 (series 3 vs. series 2) has a much tighter defined bass and a more natural midrange than either of the previous incarnations. I think one reason mini monitors are preferred the UK is that the listening rooms are smaller than their US counterparts where the larger floorstanders work much better. My 2 cents.

For lots of clean, rich detail, you might want to look at speakers with unconventional tweeters such as ribbons, Heil drivers, and electrostats. There's a pair of Heil ATM-1 speakers listed here for $600. Note that they like to be out in front of the wall by several feet.

Dynaudio