ECU flash and tune is always better than the PCV, on my ZX10R I gained 11 more HP over the PCV, before I got it flashed we dyoned it with the PCV and map that was on it, then removed the PCV and did a flash and tuned it. ECU flash is set for your bike the way you have it set up.Pre orders are being taken now for these. I've got one on my racebike (SV650) and it's considerably quicker than a standard model.
Whether you are better to just get an ECU re-flash I'm not sure as it's not my field of expertise.
Anyone in the know?
On most PCV's you run a generic map from someone else that was uploaded for their bike. Most people do not install a PCV then go get it tuned. They download the map for their air filter and exhaust and stick with it. Not taking into consideration the altitude, the temperature or humidity or A/F ratio. Dont get me wrong the PCV is an amazing tool and you will gain HP from it. If its within your budget I would recommend the flash over the PCV.
At home I have 2 used PCV's 1 for a ZX10R and one for my N300. On my CB1000R I have a PCV however no map on it, I just use it for the quick shifter. Once I seen the difference that it made on my ZX10 I was sold on the ECU flash.