I’ve fitted them to a number of bikes. Excellent quality, and makes adjusting your chain a joy rather than a chore. Downsides? Cost, I have had one set where the adjustment bolt heads started to rust, and when you fit to bikes that use a washer behind the axle nut you often need to run without the washer which means that the nut can mark the adjusters, which is a pain. I’d fit them again, and would definately choose them over the Gilies units.
Very different designs but in use lightechs are miles ahead. Gilles utilise the existing swing arm thread to adjust,prone to wear/ seizure etc, the minuscule allen key/ grub setup is just too fragile. Lightech is just more robust
I've had both and my honest opinion is Lightech all the way, I've also seen quite a few people having setup dramas with Gillies and also weak points in the overall fixing of components that fix to the mounting plates...I'm sure lots out there that have had no issues! There is also a reason why most BSB and especially road racing bikes run the lightech ... hope that helps