The advantages with the 25 acp system come more into
play when shooting alot.The orange carrier/209 primer
system was too dirty for me when shooting at the range.
The new plug also gives you a hexhead system for
installation/removal(NEF's system for this is crappy).
Also,my groups did improve with the small rifle primers.
If only shooting this rifle a few times for hunting I
probably wouldn't have bothered,but I shoot my sidekick
alot.With the 209 system,after 10 or 12 shots my rifle doesn't
lock up reliably due to all the crud in the breech area,also
the blowback was terrible.
The 25 acp system has been well worth it for me,cleaner,
easier to handle,no more blowback,and better groups.
YMMV.