I'll use it for light ground attack like I do with the fulcrum, and for air combat I don't see it being that hard to kill an eagle if you can get the jump on one....... especially if you have GCI.
If servers want the whole mig21 vs F15 thing then removing the awacs for the eagles would make it a little more "fair"..... If you're into that.
I regularly fly the Su-25A and T, the T because it's a better tank killer, the A because I prefer the look.
I've found the Su-25T can definitely give the A-10C a run for its money at killing tanks or other ground targets, and holds a lot more ammo.
The main disadvantage is of course, the avionics. Rule #1 in the Su-25... If you don't see the IR missile fired at you, your day is ruined :P
Not against the idea, but ED has a lot on their plate ATM. There's the Hornet, EDGE, Flanker AFM, FW-190, MiG-29 Model and AFM, the whole Oculus Rift thing, and probably more before they can even think about making clickable buttons for the F-15C.