5 inch krks are good at that price range. Not good at true representation of the sound. They color the sound too much, mainly in the lows. I had me told on this forum that no 5 inch monitors will truely represent bass. You then need a subwoofer, with all the problems that come with that, or bigger inch woofer. I myself have my eyes on the Adam A7x, or 8 inch if i have the money.
If you don't wanna pay that, or afford it, krk 5 or hs5 are good. You need to train your ears and get to know the shortcomings of your speakers before you can produce properly on them. How you do that? Use em a lot, listen to different kinds of music, read about them on what ppl think about the production of the track, listen to your own production on different speakers that you also know how they usually sound.