They make 10g cornies and I desperately want one, but no way in hell I'm convincing SWMBO to let me spend hundreds of dollars on one. I got my 5G cornies for average of $45 each. It IS a pain to have to rack twice, clean twice, sanitize twice, two gas line setups, etc.
cough*wuss*cough...
I transfer my finished brew, getting 6 gallons out of most batches, into two 3 gallon corny kegs. I have enough gas lines in my brew fridge for four kegs (three taps), so I have one carbonating while three are serving.
As for transferring the finished beer into serving kegs. I really like the CO2 push I'm doing. I fill via the liquid post (one on the source fermenter and then on the serving kegs) so it's very easy. Plus, once the hose is sanitized (inside), it doesn't matter what I touch it with (on the outside).
I give the serving keg's liquid post a spray with Star San before connecting the feed to it and I'm good to go.
I also clean, and sanitize, each serving keg as it becomes empty. Then I store them with some CO2 in there to keep it golden. Very easy to then vent the CO2 pressure, pop the lid, and fill it up. I pop the lid on the kegs so that I can see when it's full and I can shift to the second keg. Or when both are full, I can simply turn off the CO2 feed, remove the QD's and then vent the fermenter of pressure (before cleaning it).
Since I've been fermenting this way, I really can't see doing it any other way. Luckily, I have enough beer fermenters, and mead fermenters, to keep me going.