I had a Hassan Spark, used it for a while then put 2K into Altaros booster based system.
I gave a friend the Spark, it has been running for two years now.
To answer your questions are the junk and do they work, yes and yes. If used wrong, they can soon be junk, if used correctly they will last a couple of years, but being oilfree and air cooled they are disposable. Used wrong usually means restarting under a load or over heating.
Best advice already has been given, read the compressor section. I do believe they are getting better each generation.
Good luck,
Roachcreek