I have a Trailside I used for Steel Plate shooting. It has a nice rail on the top of the barrel, so you can mount an optic, but if you do, you can't break it down to clean it without pulling the optic off - the bolt won't clear over the optic. Stupid design!
Also, they have a cheesey piece of non-functional plastic that screws under the barrel, so the lines of the gun look better, and you have to unscrew the damn thing every time you want to clean it. Anyone who adds parts to a gun for the sole purpose of looks, especially when the part is a detriment to ease of use, makes me suspicious. They should not let the marketing guys into the design office!
I am a huge SIG fan: 210, 220, 220ST, 225, 226, 229, Trailside), but I truly feel their last few offerings to the market (Trailside, GSR, and Mosquito) are not up to the SIG standard. There is hope for the GSR, since the basic design it true and tried - SIG just needs to work out the manufacturing bugs.
Art