I used to own one of these years ago, and I no longer recall exactly why I sold it. Probably just bills to pay. So I was in the market for another chorus and reading everyone's chorus reviews and the thing that kept popping up positively for the T.C. Electronic was its low noise. Noise is my "Moby Dick", or perhaps the crocodile from Peter Pan... so even though people consistently said the T.C. sounded a bit thin and not lush, I decided to buy another one just for the low noise factor.
I found one on Ebay that was in "new" condition but which the seller clearly stated needed some repair (the effect did not engage when switched "on"). I picked it up for like $125 IIRC, thinking it would be a simple fix, like connecting a loose wire or a single bad component that I could find. His description was exactly accurate, the unit was flawless except for not producing any effect.
So I opened it up, or tried to: all of the screws were Locktited down so hard I ended up stripping all of them just trying to get the baseplate off! Once I got the base off I found it was necessary to unscrew all of the jacks, switches, and pots, which also entailed removing the knob caps. Even the knob caps proved almost impossible to remove! I ended up marring all of them with a pair of pliers trying to tug them off. Then amusingly it turns out the knob caps are in two pieces, and the pieces are held together with these tiny plastic nubbins, which naturally broke off when I was removing the caps. I finally got the whole thing apart, and proceeded to audio-probe the circuit. Nothing! No effect signal anywhere, and no place where the dry signal cut on/off or changed in any way when I clicked the footswitch, even though the LED
did go on/off!
So after a couple of hours I gave up and emailed T.C. tech support. They said no problem, just give us the serial number and your credit card number (

) and we'll fix it. I sent it off, and two weeks later it came back all fixed. For a $105 flat rate fee.

The tech note said they replaced the entire circuitboard.
Moral of this part of the story:
don't buy a T.C. pedal that "needs work"!!!
As to the sound, I concur with all the reviews I read: the actual chorus effect is very clean but a bit thin or even sterile, and not lush. The noise floor is the lowest I have ever heard from any chorus pedal. There are two other very positive things to report: one is that the chorus has a more complex cycle than the usual up-down swoosh, so it is more interesting to hear, more "natural" and less obviously a chorus effect than the standard swooshers. The other thing is the lows are killer! Not only does it not roll off any lows, but they are mighty and massive sounding!
In short, I highly recommend the sound for somebody who likes a big, tight, clean, modern tone. I would not recommend it for somebody who likes vintage-y warmth or swirly fatness... although I bet it would combine well with a tube amp, not getting too muddy in the end result.
The footswitch is not "true bypass" but the bypassed tone is very clean.