I had some very cranky DF and some that never gave me a problem. My all time favorite DF was an old Starfire 1 with the square inlets. That plane was like a Timex. It never let me down. One could get a little discouraged with the wrong DF. I have seen it often. One could also get very discouraged with a poor setup. A setup I preferred was an OS 91 with BV pipe. Relatively economical and user friendly. The only thing I hated was the Orings on pipe went bad very frequently and it was a messy pain to change them.
Buy an airframe that could be converted to turbine later, like a starfire. Probably stay away from scale and keep in mind something that will land in grass easy without tearing up, and with a wide stance. An F 16 would not be a good choice. I definately think you would be missing out on valuable experience if you skipped DF. I learned alot with DF that has helped me be to the point I am today. I recently purchased a BV F100. I'll take it one step further and advise when you make the transition to turbine, get a Kangaroo. It is a great trainer testbed that will increase confidence 10 fold.
Scott Marr