I was massively unimpressed by the two I had. The first seemed to ingest a bit of its own carb or something, and wrecked the cylinder and piston. I made the mistake of replacing it with a 4 stroke one because it was very cheap at a cash and carry and I could then re-use the attachments I had for it[1]. That had various plastic engine components, that meant it would never stay in tune for more than about 10 mins, and would also not work held at certain angles (like those required for pruning or hedge trimming)
[1] Turns out with a bit of fettling you can use them on a Stihl Kombi power head.