Hrm ... the only flipper I've owned that wasn't assisted is a cheap S&W. I do find myself playing with it profusely which is kind of funny. The thing is a turd but fun.
Otoh I've never owned a comp. lock Spyderco. I do love the axis on BMs but I don't know if that translates to the CL at all... but I think I may enjoy the flipper more.
Jeez, what a middle class American problem.
I REALLY wish I could handle both.
Oh then there's the BM 300SN. One question to those who may be reading this and have handled that knife. All of the vids I've seen have a little wrist flick when opening it. Is that necessary? Will it open easily with just the flipper? That's a deal breaker for me. At least until I've owned the other knives mentioned...
I have several para 2's one of them is a sprint and I just got the Southard today. I really do like the Para 2 but the Southard is just something else. My first flip with Southard was perfect, no wrist flick required , it then proceeded to cut me worse than any other knife

(all by my fault) it came insanely sharp out of the box. CTS 204p is my new favorite steel (even surpassing CPM M4) it sharpens just a tad bit harder than S30v but takes an extremely keen edge and just retains it forever ( I cut up a bunch of boxes with it) and the steel is further complimented by the thin hollow grind. It is so much fun to play with, even more so than my brown para 2, and it is just a beautiful knife with the stonewashed Ti and the brown G10.
Just know that the Para 2 is a bit superior ergonomically with the finger choil, good gimping, longer handle and easier to disengage lock. But the Southard has a lot more cutting length (making the most out of the amazing steel) grippier G10 and a blade shape that allows more tip control. The Southard is a lot more sturdy and will not develop bladeplay with constant flicking unlike the Para 2. Both sit in the pocket well (there is nothing wrong with the Southard's clip). The Southards gimping only works where it contacts the frame and the scale and the handle doesn't feel cramped but is not as forgiving as the Para 2 .
Overall they are both wonderful knives both with advantages and disadvantages. The Southard is more fun to play with and has more consistent prices but will always have less re sale value. It also has kick a** steel that is better than most of the sprint para 2's (IMO better than S90v) and will probably still hold an edge better than the same steel on the para 2 because of the blade geometry. It slices a lot better than the Para 2 and has an amazing action and a beautiful. high performance design.
The Sprint Para 2 is superior ergonomically (thumb-ramp, choil, better gimping), FFG blade is better for some tasks, has a much sharper tip, comes in a variety of colors (including CF!) and has a godlike resale value in the production world and is still pretty freakin' fun to play with.
It's also important to know that you can buy a Southard brand new from a dealer for $225 where all current sprint Paramilitary 2's are pre-owned (not saying they can't be in great condition) and are priced anywhere from $220-$400+ and those will be the only ones availiable until the next edition of sprint runs come out (which won't happen until at least third quarter).
I hoped I helped, you can't go wrong with either.