at the $600 for a pair price point I'm not sure, but I would suggest taking a listen to the JBL LSR305 if you can. I have them sitting next to a pair of Presonus Sceptre S6's, and frankly they do a better job than the price point would suggest (the Sceptre S6 run around $600 each last I looked).
For reference - I was using Yorkville YSM-something or other, a passive 2-way I've used for eons, and Urei 809s, a coaxial design that's even older<G>! It was time for an upgrade!
I like coaxial loudspeakers in smaller spaces, I think they behave better, a gross generalization that I am sure others will contest. But given that I tried the S6s first. It took me a couple of weeks to figure out what they were telling me, and the low end is not quite what I would like, but it is impressive for a 6" driver. I may yet try the S8s, but frankly they are a bit too large for my current set up, so I might look at a subwoofer when the time comes.
So after about a month living with the S6s I was pretty darned happy. Then a friend loaned me a pair of the LSR305s. I was instantly comfortable with them - and I don't think that has ever happened before. But, after a week or so I'm discovering that they are not quite as honest as the Sceptres. I can't really put my finger on it, but I am hearing details with the Sceptres that I don't hear with the JBLs.
The difference is not huge.
Now I've used a number of different Focal monitors in other studios. I've always been struck by the detail, and for the most part I've been able to adapt to them quite quickly. Not instantly, but not days if that makes sense. The ones I remember by name were CMS, with a 6 inch driver, a quick search suggests that they are about double your budget. But they are good monitors!
About the only 'advice' I'd offer is to maybe bump up to the 6" model if you can, it's a little more money, but I'd expect the lower couple octaves to behave better.
Again just as a point of reference, another favorite of mine is the Adam (and Eve) ribbon based monitors, but they are out of my price range, so I'll just mention them<G>!