4 stroke Magnum engines
If you are in a hurry, a novice with little engine skills, a snob or someone into instant gratification, pass on the Magnum/ASP engines.
If you have a modicum of common sense, realize that some of the engines may need returning for warranty work, are not a snob and are willing to wait for the engine to break-in before making a judgement, then Magnum/ASP engines might be for you.
Some of these engines break-in and run properly just like an OS or a Saito engine. Some may take longer than OS or Saito. One of the things you sacrifice when saving money is the instant gratification aspect that accompanies more expensive engines. That's just the way life is.
I own all of the brands of engines. I have different expectations for each brand. Magnum/ASP has its place in my shop.