Just spotted this and thought I'd add my ha'penny-worth:
I recently bought a Parkzone T-28 Trojan and a Spektrum 6 combo; Great little plane and fairly aerobatic.
Something I wasn't aware of until the guy in the shop took it out of the box is that it has an undercambered wing, so will fly very slowly.
Requires a fair bit of 'down' to stay up when inverted though!
Everything else I saw in this size range seems to have flat plate wings.
No building whatsoever required and the (very cheap) batteries swap out from underneath without any hatches.
I also bought a 'Beast' biplane, but the Trojan gets the most stick time at the moment...the name is not chosen lightly

After spending years building from plans and faffing around with 4-stroke glow engines, it's great to just decide to go flying, and actually be flying 5 minutes later!