I have the T-28 and my flying buddy has the Sukhoi and a Champ. Flying them next to each other proves the Sukie is WAY hotter than either of the other two.
If we put them on a scale of one to ten (for easy to fly) the Champ would be a nine, the T-28 would be a five and the Sukie would be a two.
Your Dx5 will allow you to set up dual rates to numb the controls of the T-28 enough to make it easier to fly. Bear in mind all three of the airplanes you are considering are low wing "fighter types" and they do NOT self correct flight attitude like the Champ does. You have to fly them every second.
I recommend the T-28. Good Luck.