I have had the Semitronic on 2 vans over a 3 year + period and find it very convenient
You need a good meter as you have to find the satellite from inside the van
I have a pro meter that that shows satellite found for Astra 2 or whichever sat you set it for
It was very expensive but well worth it in the long run for me at least
The dish is wired with a twin LNB for Sky+ and prior to leaving home I install the Sky+ digi box and the TV is a permanet fitting
I can use the TV/Sky off the inverter as well if needed
I chose the Semitronc because all the strain is taken on the pole which is fixed inside to a suitabe cupboard or wall rather than being glued to the thin roof sheets as many are
If you consider