The Para 2 was my third Spyderco, after buying a Delica and a Dragonfly 2. I've since bought about seventeen (gulp!) more Spydercos. I liked the Para 2, but at first couldn't see exactly why it was so universally lauded. Great knife for sure, but one among many.
After letting it sit for a while, I started carrying it daily for a week. I came to really appreciate the following:
1) The size is just right. The Millie is too large for my preferences. Considering the blade length, the Para 2 is very light and slim profile.
2) The ergonomics are superb.
3) The compression lock is a great design.
4) It's made in USA. I have Spydercos from other countries which I love. But USA made is always a plus to me.
5) I have come to love how it deploys. There's some resistance when you start to deploy, but once the blade clears the lock resistance, it swings open until locked. This gives deployment a feel almost like an assisted open knife. You press just enough to counter the backspring type feeling, and then it opens almost like an AO. I love that!