I have had these monitors since 2003 and I love them to death. When I chose them it was in a shootout with 7 other very popular brands (ADAMS, Genelec, Mackie, etc), and it was not even close. The most important plus of these speakers to me is the phase-aligned crossover. Most speakers seem to have their tweeters designed on Mars and woofers on Venus and then have a hell of a time making them play well together resulting in a cloudy, phasey crossover right in the most critical frequency band for music. Dynaudio, more than any other company I've seen, went to great lengths to use similar materials and design both components to seamlessly work together from the inception of the design.
It's easy to get blown away by ribbon tweeters but what at first seems like a less articulate top end on the Dyns is actually a more true-to-life, unfatiguing top that blends effortlessly with the woofer giving you a much more accurate imagine overall.
I only have one reservation in recommending them, and it's a big one. These speakers are really mid-field, not nearfield. They're big and loud and they fill whatever room they are in. That means you ARE going to hear your room for better or worse. If you are not working in a professionally designed room, then I would suggest going for the smaller BM6A along with a sub. In a good control room the BM15a don't really need a sub unless you're working on hip hop. I've found that to really get the low end accurate in my less-than pro designed room that I needed an acoustic correction system. I went with the KRK ERGO. The combination of the ERGO and the BM15a is phenomenal, but it's an expense to factor in.
That caveat notwithstanding, I can work on these speakers all day/night and feel great and the work is fun, unlike some speakers that are "flat" to the point of not sounding pleasant.