I know this is a slightly older thread, but want to add a little to it...
I've been asking the same questions...I have an Eleven Rack (and PODxt) and was looking at a powered speaker / FRFR set up - mostly for the 11r to play live. I've tried running it through the effects return of my Marshall head, but had no volume control and had also considered a Tech 21 Power amp... I picked up an L2T at Sweetwater last week, and wasn't entirely happy with it at the time. It sounded just ok - but that very well could be the 11r's presets, as they aren't actually the greatest. I have since gotten Singtall's preset pack - if you have an 11r, I highly recommend you get them. So far my favorite is the Lincoln Blues. Anyhow, I was at Guitar Center yesterday and they had the ZLX12P for $399 and I thought I would try them. They are so much lighter than the L2T, that's a big plus (but there's something to be said about a wood cab though...). Composite material vs wood. I tested these side by side, using the same guitar, cables and preset through the 11r.
I have to say the Line 6 L2T sounded much better. Noticeably more crisp - Much better sounding to my ears. The EV speakers sounded a little muddy. So that means the EV's go back. I've already packed them back in the box and ready to return. HOWEVER - I'm also considering taking the L2T back and go for the L3T. Not sure how much more I get out of them bigger speaker (other than weight! and 1400 watts)... I would like to get a big more volume. I'm not sure what I introduce by boosting the volume of my 11r at a particular power setting on speaker, I just don't want to add unintended distortion, and/or stress to the amp on the speaker.