Of those two systems, from what information there is by actual users of the products, seems the PowerTronic is heads and shoulders above the EJK. And for good reason, it covers tha gamut, whereas the EJK, is simply as the name implies, Electronic Jet Kit.
Nothing 'wrong' with the EJK, mind you. I've used them on other motorcycles. I had never heard of PowerTronic until I got the 2013 Bullet, a month ago.