Broke this away from my thread on Primestar 84E BSC-621-2.
In my opinion and from experimentation I'm shelving the BSC 621-2 because this LNBF has too many trade offs in performance. A seperate quality C-Band LNBF and KU Band LNBF will work much better.
On a dish smaller then 6' in diameter;
My findings are that at best C-Band performance is almost useless and KU Band is even worse and this is with two distance focal depths. A compromise between the two settings is even worse.
Maybe on a Prime Focus BUD this LNBF would be OK, but probably not as good as seperate LNBF's
Just my opinions folks. a grain of salt.