I would be grateful for any opinions, web searches don't seem to reveal much...

I am considering purchasing a self-launcer, likely in Ventus, ASH26, or DG808 guise and would like to know:

-do those of you who operate these or similar machines ever lose soaring days due to malfunctions in the power system?
-are there large price and/or operating cost differentials between these three?
-are there reliaibility differences?
-are there build quality/longevity differences?
-is it difficult to find informed persons to service the power system?

Thank-you