Ive owned laser engravers for 25 years. What will you be doing with your machine? If you are looking to mostly cut, one of the large chinese machines with glass tubes will work fine (boss, laguna etc) however, if you are mostly engraving like us, the big 3 excel at this (trotec, epilog, universal) the difference in both speed and quality are staggering, but so is the price.
Ive only ever owned trotec or epilog and they have been solid workhorses, running for 6-8 hours a day, everyday with almost zero issues.