A little background:
I'm turning my classic RT into a PneuMag. I have the kit and Lukes Mini Vert frame. I just ordered a Micro Rock. I have one on my other PneuMag and it seems to be the consensus best LPR for the job. I'm planning on using one of the RT's rail air ports for the LPR.

I have Phish's guide and my Pneumagger built frame to use as reference. So my questions...
To QEV or not to QEV?: My current pneumag does not have a QEV. Is there a performance difference? How noticable is it?
To Magnet or not to Magnet?: My current pneumag does not have a Magnet. Is there a performance difference? How noticable is it?
Is the Sear backstop required?: If I don't install this will it mash up my on/off?
Any other suggestions/advice/pitfalls?

Thanks. This is my first time doing it myself and I just want to have all of the information and opinions I can.

~Zach