http://www.pirate4x4.com/forum/general-4x4-discussion/708701-best-power-steering-pump-modifications-pressure-flow.html
I run a stock pump / SE 2.5X10" cylinder / char lynn steering valve on my buggy.
I updated my steering to a DE cylinder this off season. All other components are the same.
The end result was a minimal change.
Slight gain in steering quickness and power.
Better cylinder protection due to packaging requirements.
As for the SE cylinder.
Pros: off the self parts / packaging / price
Cons: uneven cycle time lock to lock (i never noticed this in mine, even at speed)
uneven power lock to lock (again, i never noticed this) if you can feel the difference then your system was designed wrong from the start.
Conclusion: I think a well designed SE system is great for 95% of what we ask it to do. I would have no hesitation going back to a SE cylinder.