I purchased these speakers along with an M-box 2 a couple of years ago to do some production work at University. These are a descent sized speaker set which wouldn't look out of place at any studio. While they're not big enough to provide killer bass for Drum and Bass production, they will do an adequate job at most styles.
The volume output is adequate for mixing but you may want to purchase a larger set for testing when the mix is complete. Most studios nowadays have at least two sets of speakers, one that is provides an ultra realistic sound perfect for setting levels and adding the correct ratio of effects to clean and then a second more powerful set with good bass response to check the mix in a more commercial setting, this set falls into the first category.
This speaker set sounds ultra-realistic and are very unforgiving with mixes, meaning that every little tweak you make is noticeable. The good news is if it sounds good on these speakers then it will sound excellent on a commercial set of speakers. The tone of these speakers is similar to the Yamaha NS-10s. These were famously used in all the best studios for the qualities I stated above.
Basically these speakers show you how things actual sound without fancy processing and bass reflex systems. While they may not sound as impressive they will play an important part in your mixing, and will vastly improve it too.
Playing commercial tracks on these speakers is also an enjoyable experience as you can more easily analyse the production on tracks as everything is clear. While casual listening maybe better off on more commercial speakers these would do a better job in terms of sound quality, although in this generation of MP3 players who cares that much about sound quality.
To surmise great realistic sound perfect for analysis and production. Commercial casual listening maybe better on speakers with a more forgiving frequency and level response, but these will happily do it but be prepared to hear what songs actually sound like.