John,
The Present vs adjustable argument has been done to death for years. At the end of the day (like most things) it's down to personal preference. Some people want a cheap option, others would like to tweak and tinker with things.
Comparitively, the Scion has one of if not the highest flow rate out there, push on/off, and is one of the better looking systems. On the other hand Pre-sets surch as the Pure Energy offer a low cost and low hassle system, which many people prefer.
Each to their own mate, Im suprised I even had to explain that to a clever fella like yourself!
Regarding a new gun, The PMI/Evil Tech's are always looking at innovating and improving products, from the low end of the market right up to top tournament gear. So I'm sure the'll be another coming out in the future. Nothing has been revealed as of yet.
Sorry if thats too much hype for you guys
Peace.
Tommy