I have just brought a E9800=MKII chrono from the bay. My R2 stopped working suddenly and online help and checks failed to sort it, so it's gone back for repair. I needed a quick replacement but didn't want to spend a fortune, [not everyone can justify a Scan, lovely as they are].
I've just had it checked against a dealers scan and its spot on. Longevity is a wait and see of course, but knowing it's accurate is a good start, also it has the ability to show FPS in one of the opening screens; with 6 pre set pellet weights, easy to access, I think it's superb value for money. I paid mid £30's for it so for me bargain!!. As for Chinese make, most chrono's are made there, not sure about Scan but I think they're still UK made, the R2 definitely Polish.
I can't comment on other makes, other than the one with the 2 big screens doesn't work for me due to having full fluorescent lighting in my workshop, and not enough space to leave it set up, my new one is only about 5 x 4 x 1.5 inches, the shoot through tube is only 25mm dia. but with the guide cone and some care it's no problem.