If you put 10 sound engineers in a room and asked them what the best monitor was for mixing on I would expect a different answer from all of them. The strange thing is all their answers would be correct.
No monitor is the same, some sound more forward in the mid range, some give more bass and others sound really boring to listen on. The point being is you need to like or more importantly know what type of monitor would suit you for your mixing. Its all personal taste. What you don’t want to do when comparing monitors is put on one of your own mixes and pick the monitors that make it sound great. Put on some CDs of music you know the sound of and then when you think you have one or two sets of monitors that sound good or great put on one of your own mixes possibly one that you were never really happy with and youk now it needs some work to make it better. Listen and see if you can focus clearly what needs fixing in your mix. Out of the two sets the one that sounds the best for commercial CDs and gives you clarity on your mix is probably a good choice.