Yong Heng are great value for the money and I hear the newer version are even more robust I believe the piston and o rings are better quality . Mine started leaking air from the vertical tube lower fitting so I took It apart and found the o ring on the valve ( the one with the spring attached ) looked a little worse for wear so I replaced It , but no luck still leaked maybe even worse than It was before I took It apart . while I was at It I took the head of checked the piston rings and o rings all seemed good , I thought about buying a kit for It but like I said water and oil changes got old and I thought hell this Is a good excuse for a new compressor and mine didn't have the shut of valve so I had to hang around while Yong did Its thing . As Worriedman suggested I might buy a repair kit and If that fixes It keep It as a back up , but for the $$$ I would recommend the Yong Heng to anybody .
Big shout out tp PA I know they have been getting a lot of stick lately , I ordered the Hill on Friday got It on Sunday morning and free shipping not to shabby , the Hill has been out for a year + now so I was thinking hopefully all the teething troubles have been sorted I know there was a software problem at one point , anyway the Hill was delivered today the box was In great shape no damage did the prep work on the Hill filled my FX dream line tac from around 120 to 250 bar In about a minuet ( I have a 300cc bottle on It ) a little smaller than I thought but that's fine and I would say half the DBs of the Yong Heng so pretty quiet.
So far so good no regrets about buying the Hill compressor solid and well built seems like a nice bit of kit .