My recommendation is to go to your local flying field and see what engines the members are experienced with. If you choose the local favorites you should have no problem getting tuning assistance at the field. If your engine has any quirks the members who are familiar with the brand should be able to help you out. I have two MDS engines. I got them for next to nothing at a swap meet. One is running great on a trainer and I am looking forward to trying the other one. I think it was abandoned before it was even broken in.