Yeah, mine does the same. I have to use a lot of down elevator to make it come down. Not sure it's tail heavy, because it has none of that telltale twitching. I think it's just the way the plane flies.
Just got out the balancing jig. It was way tail heavy. Moved my 2 cell 2300 A123 forward to the motor box. About a foot. Now it is close to the forward balance point of 5 1/4 inch's from the leading edge at the root. I think it's been tail heavy for years! Bet it will fly better now! Probably wont snap as smartly but I hope it lands better. It was a handful to land on a windy day at a small field!
To be fair, I did put my rudder servo in the rear as a push pull instead of pull pull. And it has an MLD-28 in it which is a light motor.
I flow my son's 72 Extra at Fly Low Event event in Tennessee and it flew great. It landed like a Slick. It is electric but I won't hold that against him. He just does not have the Internal Combustion Bug yet.