Just to throw in my .02...
When I migrated to the 9400, I tried both editors and looked @ the pros and cons of each. My final decision was to utilize PEPv1 for the majority of the 'build'. I did abandon the 'hidden page of codes' concept and implemented the use of the custom device database in PEPv1. My reasoning for this is fairly straightforward:
I can build whatever I want in PEPv1 (utilizing the DB of course) and prefer to do so as I still prefer the GUI over PEPv2. I can do any ProntoScripting I want under PEPv1 (it just may not run in the simulator). So I design and SAVE under PEPv1. Then when its upload time, I open it with PEPv2, tweak the WiFi settings (WPA) and upload.
That way I get the best of both worlds.....