I have not- but have had experience with a few Asian manufacture swap out engines.
Kind of a lottery- the ones I have seen do not replicate the power of the originals- are not nicely made or well finished. Can do nasty things like throw wrist pin clips, piston ring retaining pins, peel the lining off the cylinders (thats why I get to see them!)
But you lay down your money and take your gamble- hell of a cost saving versus replacement OEM stuff, you get to learn how to pull one down and put it back together again- will cure the compression issues and hopefully most of what may have caused the meltdown in the first place- but will not cure a no fire situation if you are talking no spark.
If it is a saw you do not depend upon, do not use much or use hard- then Chineseify it- you might get a good one that lasts a while.
