I am not sure exactly, I use a JR radio and the the flap is not centered by default, so I am using -75% and positive 50% if you understand what that means, I will need to confirm that, I just adjusted the settings recently.
Also, I think its worth it. This plane does not have enough wing area to have floaty landings, so in most cases, its a hot fast landing, with the flaps i find that i get a bit of a slower pace, but i do need to add a bit of up trim when i kick in the flaps as my nose seems to bow a bit, which i guess is normal. but it definately helps though, bigtime.... this is also not a plane i fly every week, its been 8 months since i last flew it, so I will let you know how it performs this saturday!