OK, had my 1st rehearsal with the CLR active wedge last night. My impressions, most of which will echo what others have already posted:
1) It's darker sounding than my K10 and my AKG K550 headphones. Or, to put it another way, I can now hear how hyped the treble is on the K10 and the K550s. I have to re-tweak a lot of my rigs now that I have a truly flat reference to go by. If you've looked at any of the rigs I've shared you'll see that I often have the Treble and/or Presence dialed way down. I'm finding that I have to undo a lot of that.
2) I like the sound of my KPA through my K10, but with the CLR I feel like a layer of artificiality has been stripped away. It just sounds and feels more like real life and less like a recording.
3) It works great for monitoring both my guitar and vocals. One nice surprise: my voice doesn't sound quite as thin and reedy through the CLR.
4) It's powerful, more than capable of flattening my bandmates in a 24'x28' rehearsal studio. I had the master volume set at 50%, input 1 (guitar) volume at about 30% and input 2 (vocal) volume at 100%. The KPA master volume was at 7.0.
5) It's built like a frickin' tank. The K10 at 32 lbs. feels like a plastic shell with stuff inside it; the CLR at 45 lbs. feels like a bank safe in comparison. I can't believe I used to routinely gig a 45-lb. tube combo and 22-lb. backup head. But the handle is extremely comfortable and well positioned for balance, so carrying it (short distances) isn't really a bother. I only ran into trouble when I tried to lift my handcart with my KPA, CLR and duffel bag all strapped in together. I can do this with my K10 when the taxi trunk is big enough, but with the CLR I had to break everything down in order to load in. Kinda sucked with the crappy weather last night. I guess I need to work out more.
6) The main feature I miss from the K10, besides the size and weight: the K10 volume knobs have little detentes so that you can reach around and set your levels sight unseen based on the number of clicks. The CLR's volume knobs rotate smoothly with no detentes. They do have a little ridge to indicate the direction of the knob, but I don't think I can reliably set my guitar/vocal mix without eyeballing it, at least not yet. The knobs are also somewhat easy to accidentally turn if you brush up against them. On the other hand, it's nice that the rear panel is perfectly vertical when the CLR is in wedge position. With the K10 in wedge position the rear panel tilts down into the floor, which is awkward for checking settings and connecting/disconnecting cables.
Hope that helps everyone considering making the leap. My K10 will be for sale shortly.