I dont think you can go wrong with either. There is a pretty substantial price difference here, so, if you want to rock out- you may want to get the Soliloquy's and get a good sub to go with it. I havent listened to the ProAc's much but I have owned and loved the 5.3's for a few months. They are excellent on every kind of music to my ear. I have been powering them with a BAT VK60 (60wattsX2) and feel that this combo is tuff to beat. Good luck.
