OK I was at Frys Electronics yesterday (mistake no. 1, I know).. And they have the discontinued Sony A4 Sat Receivere and next to it the Sony A50. I couldnt figure out what the differences were. I asked the sales person and her big answer was- the A50 is the newer model. Anyone know WHAT features the A50 has that the A4 doesnt and if its worth spending an extra $50 to have the A50?