I have a Super Tiger .45 in mine and it has all the power I can handle, but the SSE could certainly handle more.

A lot of people eschew the rubber-banded wing in favor of wing bolts. Be sure to beef up the fuselage sides if you do this.

A lot of people relace the rudder-supported tailwheel wire with a fuselage-mounted type. I went with rudder-only and haven't had any problems, but I reinforced the rudder with plenty of epoxy fiberglass.

I'm not sure I'd go with a pull-pull system, but I did replace the supplied pushrods with Sullivan Gold-n-rods. Sig did a beautiful job of engineering the controls--no measuring, no planning, no figuring out control horn locations--then furnishes some pretty flimsy nyrod.

Some people suggest sheeting the turtle deck, for looks only. I didn't, but I extended the scalloped fillets about an inch more than the plan shows, and the turtle deck looks good.

Some people replace the LG hardware with real axles and collars. I didn't, but may yet. Wheels are way loose.

Some people consider building a hatch for the fuel tank, but I'm not sure if anyone has. Reason for a hatch is that (despite what the plans say), fuel tank installation is permanent. With the wing tube holder glued in place, the "standard 8 ox. Du-Bro tank" is not removable. Some people don't glue the tube holder in place, so it can be slipped out to allow access to the tank. That seems like a big compromise. Choose your tank wisely and build it kink-free. Reasons for NOT building a tank hatch:

1) Too much effort for an otherwise easy-to-build plane
2) May compromise structural stiffness
3) Sig tells you not to

This is a terrific plane. If you like taking pictures, start a build thread in the Kit Building forum. Lots of SSE builders out there.