I've been switching between my KnH o300 setup and my pelonis 42 setup. I'm not in love with what I've got going with the KnH setup in regards to 5.1, but I do absolutely love them for stereo mixing. I tried to make due with a 0110 for the center, and in my opinion, the 3 front speakers need to match.
The lower mid of the KnH are very tight and precise, and I think part of that comes from the sealed cabinet. When I switch over to the 42s I notice a bit of tubby-ness, while also noticing the drop off in LF extension. It's not a problem, the 42s are a perfect smaller, and closer to me reference. My third is a single driver setup. I've hesitated buying the sub for my 42s since I've never gotten subs to work for me. I'll be very tempted to move over to a 7.1 4288 system if they come out with a center channel/sub combo. The 42s are amazing for how big they are, and for how much they cost. If you don't get a set of 4288s, you just just get a set of 42s, even if they are just for your computer rig!
I had a thought about buying 2 42LF setups to sit under the 42s, but wouldn't that result in twice as much bass as would be needed, or could the CP control adjust for that? As a side note, CP control will not see my amp, so I've never used. It. I've tried everything, including installing the driver multiple times. I'm running Lion 10.7.3