I believe the SRA secondary is either 15 or 18%, depending on who you ask.
Given the low cost of the secondary GR (about $55 for the two gears) and the relative ease if install, I very much recommend it.
Keep in mind that you will have to shave the speed sensor down a bit to get the speedometer to work, and for the auto shifting to work after you do the GR.
In auto mode if you go WOT it will bounce off the rev limiter unless you add a shift module from Rapid Revolutions (another $175ish IF you can get one, they are rarely in stock). You can get a shift module or simply change your driving habits a bit, as simply letting off the throttle for a second will make the bike shift.
I think it would be perfect with light 27's (like a Zilla or Mudbug). 26's has no power issues in thick stuff at all. Good enough that I think a light 27 would work well.
2005 Foreman Rubicon Camo
Perfex, 27" Mudbugs
Heated grips and Thumb , HID's
5K Viper Max winch
2009 Foreman 500FM Green
Perfex with HL springs
27" Execs on Rubicon rims
Heated Grips and Thumb, HID's
4K Viper Max winch
2006 Foreman 500FM Green
28" Mugbugs, stretched, Perfex, HLsprings
3K Superwinch winch
2009 475 Rancher AT Tan
26" Mudbugs on Rincon rims
Warn winch. Foreman pod light with HID, SRA gear reduction