Built two midstars the only mods I did were sullivan tail wheel bracket instead of the stock one and make it a tail dragger.
I have it for three years now and its a stubborn airplane crashed it twice nose into concrete and its still flying well.
knife edges, rolls in a circle and turns on a dime like there is no tomorrow and its coming for more.
sometimes I think my 46 AX on it is over powering it, this airplane flies on its wing not on its motor so there is no need to go crazy.
Sig midstar is a great airplane.