My buddy has APC9 and I have Z-5RS.
My MP5 clone is softer to shoot, but I LOVE the ergos of the APC, it’s like a baby scar and it’s built beautifully. However, anytime I take people to the range, the MP5 is the belle of the ball.
All that aside, I didn’t already have the Zenith, I would pick up a B&T. One with a Glock lower since I have endless Glock mags. In fact, I may pick one up eventually anyway if I find enough spare change.
I hope that helps.