Interesting; my running shoe shop recommended the 2120 to me when I expressed fears that my 2110's feel to have too high a profile for trail running (they are great for road running). I tried on the 2120's & just there in the shop, didn't feel the difference I'd hoped to feel (i.e., to feel a bit shorter, esp. at the heel, I guess). My search for such a shoe started when I rolled my ankle off the edge of some pavement in December - and because in the summer I like to do trail-running.

If you do decide to stock up on the 2110's, psst, that model appears to be on sale at
http://shopseejanerun.stores.yahoo.net/as2110.html

NOTE: on that site, the 2120 is described as a trail shoe, while the 2110 is not. Trail shoes tend to be stiffer, as well as lower in profile.