Year before last I would have picked Leatherman Super Tool 200. Since then, even though I liked it well enough and wasn't really in the market, I have acquired several other makes and models, purely because they were available cheap. My intention was to try them out in comparison, determine which was best, then sell off or give away the others. In some cases I have done so already, and have so far actually come out a little ahead, thanks to blowout deals, often from alerts posted on this forum (Most Grateful for those). Problem is, I grew fond of most and am finding it increasingly difficult to cut

any from a collection I never wanted in the first place.
If, however, I only had to choose one, it would be a larger model. It may be overkill for most uses, but there is no substitute for tough enough when needed. That eliminates the Spirit, PST, Juice, Micra and Squirt, nice as they are. Anyway, I carried a Super Tool as EDC for several years and consider the weight no big deal.
In current rotation are my old standby ST 200, an original Swisstool found last year, and a Core picked up at a Target clearance sale in January. At this point the jury is still out. There are things I like and not so much about each of them.
This can go on for years. I'm in no hurry.
