I cancelled my EF 76/83" MXS order yesterday.
I was PM'd by a reliable source who owns the plane that he is not optimistic about how the plane/CG will handle a DA50 with a pitts muffler. I share his concern and will let others figure it out. I never found a good engine match for my EF 78" Extra and spent too much time and money trying.
The MXS is in every way bigger and about 1 lb. heavier than the 78" Extra. A DA35 will need a pipe to move it and by that time I might as well buy a 30% plane.
IMHO - EF should have made this plane for the DA50 there are plenty of them still around.
That simply isn't true. I had a 78" Extra with a DLE-30. It's what I had laying around, the plane could have really used a bit more motor, but I was able to hover, and pull out and do all the tricks with it. It came in at 12.25 lbs I believe it was. I also had a 76" MXS, with a DA-35. Otherwise both setup the same. Same receiver, batts, power, fuel tank, switches, etc. The MXS was 12.5 lb. So a 1/4 lb difference is all. Not a whole pound. I flew mine on the DA-35, and honestly I feel it's probably enough power. It's very similar to your average 50cc plane like say a 3dhs 87" Extra 330, or 89" Slick on a DLE-55. The problem is that me, and probably others, have gotten used to the power/weight ratio of the 60" EF planes. And those are ridiculously overpowered. And so a part of me (big part) wants that type of power on the 76 and it just isn't going to be there. Not even on a DA-50. Also the 76" MXS flies quite light on the DA-35, very floaty feeling. I don't think the extra weight of the DA-50 would be a problem at all, and if balance is an issue, add an ounce of weight on back by the tail wheel. It will balance then.
I agree that the cost and everything else considered you can nearly buy a 30% plane instead of the 76 MXS, but for me, the transportation of the 76" MXS is much easier than the 30% class, and the agility of the 76" planes is a bit more too. They can be thrown around easier and a little more aggressively. The 30% ones slow down a bit and don't feel quite as fast or loose as the 76" MXS does.