RE: 4.8V versus 6V for receiver battery?
For what it's worth, here is my experiences. I have two planes currently making the trip to the field. Both are using Futaba S3151 digital servos. The first is a 4*60 and I'm running five servos in it. Also 4.8V. The second plane is a Ruperts Dad scratch built and it has six serovos and a 6V battery. Both are Nicads and 1000mah. I also run VoltWatch sticks on all my planes. I can fly the four star as much as I want to fly in a day, usually about three tanks of fuel, or around 40 minutes total filigh time. The Volt watch will show the battery down about 1 or two lights. The Ruperts on Sat had three short flights of about 5 minutes each and when I put it away for the day, I was down three lights. When I got it home, I cycled it from where it was and I had 63 minutes left at a 500ma load. I'm guessing I could have gotten another 20 minutes filght time if I had wanted to.
The comment about being able to use a standard battery charger is something to keep in mind. I only have one 115vac charger that will charge a 6v battery, but I have three or so of the wall warts that will handle the 1000ma batteries OK. If it wasn't for needing more nose weight on the Ruperts, I think I would fall back to a 4.8v battery. I'm not a good enough flyer to be able to tell the difference.
Don