From pistol-training.com SHOT show report:
My personal favorite new entry is the SIG-Sauer P229 E2 (pronounced “E Squared”) that was mentioned here last week. SIG handed me one to play with and it was half an hour later before I gave it back. Here is the big deal with the E2 guns: any existing P229 or P226 can be turned into an E2 simply by changing some parts. The main features:
•A smaller and slimmer snap-on grip that doesn’t require grip screws. The grip actually attaches internally to the grip screw bushings, though, keeping it very tight on the pistol. So tight, SIG is developing a tool to help users take it off. If you don’t like the small grip, you can easily put any of the standard SIG grips, Lasergrips, etc. on the gun simply by using grip screws.
•A short reach trigger with SIG’s (poorly named) Short Reset Trigger, or SRT. The SRT isn’t actually a different trigger, it’s a different internal lever and sear. After nine months shooting the HK P30, the SRT was just ludicrously short. A P229 or P226 with SRT is still, in my opinion, one of the fastest-shooting pistols on the market.
•A modified decocker lever intended to eliminate the problem some people have accidentally disengaging the safety due to their grip technique.
•A recontoured slide release lever — actually, the lever from the X5 series — that will definitely help people who complain that their slides don’t lock back on the SIGs because of a high thumbs or thumbs-forward type of grip.
That's very interesting, I would like to try those new grips if they do fit on existing models!