YS1500 vs Pitts and SPitts

I was on the phone earlier looking to order a YS1500 and the salesman on the other line mentioned that pitts and spits model is quite good and has PID controller and is fully welded. I know people have asked the question before about the PID and the general response has been that the yoder firmware is better. Can someone explain why its better? Also does yoder YS1500 come fully welded?