Thanks for the info. So besides the 3.0 being bigger, are there any advantages to them. Stronger, better ride, or more travel???
Not exactly "better", other than the diameter increase they are internally and externally identical. The reason the shock bodies have larger diameters (currently 4" is the largest) is for the race environment. Just like radiators, in racing, larger shocks mean cooler fluids, gases and shock components. Larger surface areas dissipate heat quicker which reduces shock failures and allows the shock to continue it's intended compression and rebound rates over longer periods of race conditions. As for how the 2.5" shock works compared to the 3.0" shock it's pretty much identical.
Truly, unless you live out west, do tons of high speed off-road driving of long distances, you will never see the advantages of how a larger shock will help your vehicle perform better. When was the last time you drove above 40-50 mph for at least a 1/2hr constantly in an offroad environment? For 99% of the offroaders, never.
Now step it up to a DTD scenario, true overkill for practically anyone who does not have access to areas like we do in NM, AZ, UT, NV, CA. If you can't see the horizon when you are offroad, you probably don't have the area to carry the kind of speed to justify owning a set of coilovers and bypass shocks at each corner.
Just doing the average type of rock crawling and muddin? Just get a set of EVO bolt ons or their weld on coilover only set up!