In short, lot of dynamics and impressive sound pressure but not so good in terms of quality.. Of course there is also good active monitors available but then the pricing will go up just like with other solutions also. I would much prefer Behringer models over KRK any given day in this price range.
Here is on vid you can compare KRK, Yamaha and JBL monitors, that might interest you..
Loricraft / Garrard / SME / Transfiguration / Dynavector / Ensemble / Auditorium 23 / Shindo / RA / Audio Note / First Watt / Duelund / Altec