My first Spyderco was a base (hollow ground 154CM, solid liners, black G10) Manix2. I thought it was the best thing since sliced bread. After about a week of carrying it, though, it started to seem a bit heavy and bulky in my pocket. Still fantastic in-hand.
I picked up a FFG M4 skeletonized-liner tan one - it feels at least as solid, is noticeably lighter, but still feels like it takes up my whole pocket (I deep rfp carry. When I clip anything, including a Leek, to my pocket it makes it very uncomfortable to get my keys out. I have pretty big hands - size XL to XXL gloves.)
Anyway, based on trying an PM2 at a shop, and all the glowing reviews, I ordered the M390 one and can only agree with the above. It is awesome, and IS my EDC.
It's an amazing slicer, holds a razor edge forever, simply feels like an extension of the hand, and opens and closes like butter. And, although it's slightly longer and only slightly trimmer that the Manix2, it's lighter and carries like it's about 2/3 the size. I can feel it in my pocket just enough to know it's there, but it never gets in the way, or makes me feel like it's just sitting there like a lump.
So, for me, for EDC, it's an upgrade. As far as design or performance, it is merely a different way of doing business. Both are great.
I keep a Manix in my trunk, and usually have another in my jacket pocket, in case I need to do something that I may be afraid will gum up or damage the tip on my (rather pricey Sprint) PM2 (or, heaven forbid, misplace it), but there is no regular cutting task I don't think the Para2 is up to, and for me it the the perfect EDC.
YMMV - good luck with your choice.