Hi coop1957
I have a Leatherman Blast and think it is an amazing tool. I have had mine for a little over a year, and find that most of the tool blades have loosened up with use. Some of the screwdrivers are still a little difficult to open, but I am not sure if the lock contributes to this. I have heard about people "flicking" open their Leatherman tools to expose the pliars much like the butterfly knife, and mine will do this very easily. My Blast goes into the sheath pliars end first, and there is considerable "play" with the tool in the sheath as I can hear the tool rattling in this position. With the lock end down first, my tool snags on the sheath with removal, presumably because of the design of the lock (i.e. the end of the lock that is depressed asts like an anchor, as it sticks out farther than the end locking the tool: hope this makes sense?).
Anyway, I use my Blast daily and love it. I also use a variety of Vic SAKs but find myself returning to the Blast for EDC.
Since both handles are the same from the outside, I have placed a small strip of duct tape on the side with the blade so I can find it easily. Also, I use extra virgin olive oil on the pivots of the tools as I use the Blase for food preparation as well (never know when you will be need it as your sole means of a survival tool). I have not had any problems with the blade or tools seizing up from using the olive oil, and it does not leave an odour on the tool like WD-40, but then again this has been my experience.
Sorry for the length of the post, but I hope it is helpful.
Best regards,
Neil