The Momentum 3is are very very good. They paint a very vivid picture right the way through the frequency range, and they are just great where it comes to punching out big dynamics. They are also very clear and intelligible at low levels.
The only words of caution I would give are a) you need to have a big enough room if the bass isn't to dominate - mine is 3.7*3.7m and i have them about 45cm from the rear walls and 65cm from the sides and it's pretty borderline. On most tracks they sound just great, but on a few where the bass has been recorded deliberately on the heavy side, it can sound a bit overbearing. b) the treble can sound a bit harsh if you push the volume up when listening to a poor quality recording.
Neither of these provisos is the speaker's fault in my opinion, but depending on your room and the sort of music you listen to they will may not be the best choice. Either way definintely worth a (home) demo.
What is the rest of your system?