I had a play in Turnkey with a wide array of speakers. Ended up with Alesis M1 Actives, £270. They're lovely... The results of my meanderings are in the trance forum...

Everything else (active) in the price range was too hard sounding in the upper registers, causing fatigue. I can listen to the Alesis for ages without problems! The rest lasted minutes... :o

Compared to even the more expensive (like, £3000) monitors, they had more bass exposed. This could be due to a subtle lift in the frequency response at this region, but it allows you to get more of an idea of what's going on down there... The upper registers seems a little lower than an ideal flat response, but this isn't really a problem. As long as you know it's there, you can still hear all that detail.

Ben