Alex,
Good review, I see that you have some of the same concerns as I do regarding the Spyderench. The gadget factor is much higher than the utility factor generally, and the possibility of losing parts is high in the right environment.
From reading your review I think I may have a somewhat better example than you got in terms of fit and finish.
I carried mine religiously for a period of several weeks in order to form an opinion, but I carried it in addition to my Leatherman Wave, not in place of it. There are tasks that this tool can do very well. There are also tasks that It cannot do at all. For me it will never replace my wave.
I think part of my difficulty was that I undertook this trial in the middle of the winter. Working outside in the cold and snow you appreciate how easy it would be to lose a part that would cripple the tool.
None the less I say hold on to it. It is fun to play with, and some day it will be a collectors item. I don't think Spyderco is going to make that many of them before they get discontinued or redesigned.
Mike