Having flown both the Showtime (with and without the wing fences) with OS 120 AX and the Excelleron with YS 110, I much prefer the Excelleron as a much more neutral and positive airframe. I have a very minor rudder to elevator p-mix in the Excelleron to hold knife edge and no rudder to ail mix at all. The Showtime required both and the ail mix was pretty substantial (11%) at max deflection.
I suspect you could turn the Showtime into a moderately successful pattern model with time and effort but the Excelleron is darn good right out of the box. Now, that said, I used the canopy and LG off an Icepoint for more side area (and better profile) with the canopy and more ground clearance for a 16-10 prop with the LG. I mounted the fuel tank midships (thanks YS) and the CG stays put througfh the whole tank.
Gordie