Howdy from Texas. I own the Soliloquy 5.3s ( no i) and really enjoy them. I have never heard the 6.3s or 6.2s, but my "HT Room" is only about 11 x 15 or so, so the 5.3s are best for me. Since owning these, I have no desire to upgrade at all. I listened to TONs of speakers over months before I purchased these and other Soliloquy models. As far as bass, its really good. The way they employ the two 5" drivers and cross em works suprisingly well. Bass is NOT a problem, but I can envision the 6.3s giving more, simply based on their driver sizing. It is a must to put the 5.3s 3 feet from the wall, otherwise bass can get muddy due to reflection from the rear port. The longer they play, the better they sound. The soundstage is par excellence. You can be anywhere in the room and still enjoy the stage. Also, you dont need huge upgrades elsewhere in the system to get a great result. The cabinets are awesome and look great. AS far as comparing brands, I have the following comments; Vandersteen is a totally different sound. Thats all I will say. I would compare Linn Speakers, Meadowlarks, maybe Joseph Audio and if you can drive a 4 ohm speaker, Magnepan 1.6s. Of course there are a gizillion speaker brands out there, but these are my suggestions.