I believe beam divergence and reticle are two.
It's not in the same league as the Terrapin, then again neither is the price.
I'm tempted of buying the Sig and selling my Swarovski, simply because of the continuous ranging and seems to be less susceptible to shakes. The Swaro is great, but if you can't hold it still it won't give you a reading past 600ish. Could be argued a good thing though as a false number isn't a good number.
2400 has me at sticker shock. I missed out buying a Terrapin when they were $1750 new, thinking that was ridiculous in price even though I've experienced how awesome they were. Now I'm not so sure. I guess having ballistics in the finder would be handy and reduce the additional gear needed to shoot.