legacy vs pro
Well, for the limited discussion of running two 301 receivers on either kind of
twin, the answer is : not much.
Neither needs any additional hardware to run just two receivers.
DishPro Twin:
long cable runs possible (200 ft)
high quality cable needed on longer runs
quicker to run switch test
adding more receivers or
one more satellite is easy with the
DP34 switch
only works on the newer 3-digit model number receivers (need
adapter on older 4-digit receivers)
might be
cheaper at around $60 for dish 'n lnb
Legacy Twin:
cable run generally limited to 100 feet
limited to two receivers - not really expandable
can add 3rd satellite with
SW21 switch (one for each of two receivers)
works with older and newer receivers
might be cheaper if you find one around the neighborhood for free
Most of the things under Pro don't matter for most people, so either would work for you.
I actually caught a guy on the way to the dump with his dPro 500, 2nd dish, and dP34.
I got 'em for free, but gave the guy $20 anyway.