I’ve got an older TMars dropper that I’ve had on my bike for a year plus, no problems at all. Yes I had to give it a service to keep it running sweetly but it’s really easy to do and takes a few minutes.
The only niggles that I had were that it’s possible to over lube it (seems counter intuitive to me) and the inline adjuster on the cable was a bit over-sensitive, I’d give it what felt like a little jib to try and get the ‘lever’ throw spot on and it’s be too far gone the other way.
I got a deal on a hydraulic post otherwise I’d still be happily using it, as it is it’s sat in the ‘to be sold when I can get my act together’ pile. If you’d be interested I wouldn’t want as much as £50 for it. E-mail in profile etc.