If you do a search you will find many varying opinions on this subject. I have seen folks that like one or the other and hate one or hte other. If you are not in a hurry and are willing to do a little experimenting the thing to do is to plant small plot right next to each other of serveral types of mixes then judge for yourself.
Personally the Imperial clover has worked well for me and so has some of my own clover blends.
If you try the small bags you wont be out too much except time and you might be surprised by what you find.