Actually, the RPM is like the Rolls-Royce of Ion triggers, so it's a little over-priced. It is the vbest trigger you will ever feel in your entire life if you set it right, but it's still 50 bucks.
All NDZ Triggers are very good triggers with smooth pull and good adjustability/user-friendlyness.
IMO, the stock board should be left untouched until you have upgraded other key features of the marker. The stock board already has fully adjustable ramping, semi, burst, and full-auto. The rest is all luxury.
And finally: QEV's pwn all! lol. A QEV is possibly the best upgrade you can get for the money.