I actually did try them a few weeks ago at knifeworks and was surprisingly underwhelmed by both. I think most of that is due to me realizing that I'm just not a fan of flippers, but on a smoothness scale, I didn't find either to be as smooth as a GB, manix 2 or pm2. Just my opinion based on the two knives I handled. Great products, just not for me.
Yeah, my manix 2 was a very smooth knife too. As far as dropping open...I didn't really clarify, but I think there is a difference between loose and smooth. My PAC salt certainly has more resistance than my manix 2 or pm2(both of which would free fall closed when the lock was pressed. The PAC salt has more resistance (due to the nature of the lock) so it won't free fall like that, though it will slowly close under its own weight. I think what I mean by smooth is how it opens without the slightest grind or hitch. Yes, there is some slight resistance compared to some other models (again due to back lock) but it's completely fluid in the movement. So even though it requires slightly more force to open than my pm2, I find the movement is actually smoother if that makes any sense. Overall I find it more smooth than the regular frn models too. As bedgoo pointed out, maybe there is something to be said for washerless.