The Tonelab is great!
A few years ago (actually, right after I got divorced), I decided I needed a better distortion pedal.  So, I started surfing the internet and found out about modellers (I had been out of the loop for a while).  I lived in a small town at the time, and couldn't try anything out, so I ordered a POD 2 from ZZounds sight unseen.
To be truthful, I thought the POD sounded like a turd.  I was about ready to send the thing back.  Then I plugged it into my JC120 and found that it could make some pretty good noise.  Not great, but pretty good.  Basically, I saw it as a fancy distortion pedal.
Fast to this January when I bought a Tonelab.  The Tonelab is in a whole 'nother league!  I couldn't stand the direct sound of the POD: it was really muffled, like a wet blanket had been thrown over it, and the dynamics were poop.
Not the Tonelab.  It sounds great!  Plenty of presence, and the dynamics are wonderful.  In fact, there is so much available presence, that if you're not careful, it can sound a bit harsh.  Just play with the Presence and the VR Gain knobs if it sounds too bright.
Anyway, I give it a big thumbs up, except for the software.  Despite the huge number of Macs used in recording, the folks at Vox decided to make it PC-only.  Doh!  At least the Line-6 folks were smart enough to write it in Java (and with their new system, you can surf for POD patches, and they will automatically upload to your POD.  Cool or what?).
IIRC, Vox gives the Midi codes in the back of the book.  If I had the time, I'd write my own Cocoa app for OSX.  Maybe some other intrepid Tonelab owner will pick up the challenge.
The only other thing about the Tonelab that is uncool is that the foot controller is extra (and quite a few bucks).  But rating it on tone and usability, it's been great.