hello all, just wondering who makes the glow engines for tower hobbies, what is everyones experience with them. i know o.s. is or has usually been the bench mark for glow engines, but they are usually twice as much as everyone elses. ie. ( evolution / tower hobbies / super tigers ) looking for a good replacement to put into my hobbico hobby star .60 trainer and make it much more of an advanced trainer thinking about the .75 sizes ?

thanks again for all the upcoming info, help