Warning: Rant Incoming!
The Para2 is an amazing knife... one of the coolest knives around actually... except for one thing. The QC on them is pretty sketchy. I've owned 7 (don't own one now, but will again eventually I know) and of those 7 only 2 were well built knives. The other 5 had significant significant (unacceptable) blade play issues that either couldn't be adjusted out (ie, you could tighten the pivot all the way down as tight as it would go and the blade play still existed) or if you could tighten it out the free swinging action that is the hallmark of the Para2 was ruined (BTW, I know all about the pivot bearing system, but irrespective if it, some Para2s can be tightened completely down and still have free action and some can be tightened down so tight that you can immobilize the blade... Spyderco's pivot bushing system is no where near the quality and/or functionality of Chris Reeve's).
I am probably way pickier than most Para2 owners and many may disagree with me and think their knives are well built, but as I said, I've personally owned 7 and handled enough others that weren't mine to see the trend of sketchy QC when it comes to consistency in build quality. It's really a shame because the Para2 is probably my 2nd or 3rd favorite knife of all time, but I don't own one because I can't find one that's built well enough to justify the $100+ price tag. It's very frustrating and frankly Spyderco can (and should) do better. The first 2 Para2s I ever bought were perfect (no blade play, perfect action, perfect lockup, no lock stick, etc) and that's how I thought they all were. I sold them to help fund my first Hinderer purchase thinking I'd just get another later when I had the cash... but like I said, every one I've bought since has had issues.

But I will keep searching... the design of the knife is so good that it's worth the hunt.
As to the 0566... it's a great knife too... and built better than the Para2 IMO. Well, at least that's my opinion so far. I've owned two of these as well (sold one to a friend). And both were solid as a rock... zero blade play, bank vault lock up, great action... and both flipped amazingly once I ditched the spring assist (which I dislike!). I do wish it had something other than Elmax for blade steel... not that I've had bad luck with it so far, but ZT's Elmax has a pretty spotty reputation. I would have preferred some good S30V or S35VN (or M390!

). But I can live with it. I do think the 0566 is a bit over-priced though. For a spring assist SS framelocked knife $144 (the usual going rate from what I have seen) is a bit high... not terribly high, but high. But seeing as it's a Hinderer design (and a dang good one) I suspect the price has to be adjusted to account for the cut Hinderer gets on each one sold (BTW, not judging Hinderer in this regard at all... he should get his cut, it's his design!)
Which would I pick? Well, if the Para2 was built like it should be... then the Para2 hands down! As I said, it's an awesome knife (when well built). But if I was just ordering one blindly from a website and I wanted to be sure I'd get a well built knife... I'd have to go with an 0566. Its QC (at least thus far) is much better.
I am really starting to wish Spyderco would build the Para2 in Taichung. Taichung Spydies are world class knives when it comes to build quality and the Para2 (which is a world class knife design-wise) deserves world class build quality too. Alas, Golden isn't able to provide that lately it seems.
Okay, rant over.
