I think I'm in my fourth season with Microspikes (on my third pair, not due to failure but wearing down of the points). The answer to the original question is not what has the most traction (longer spikes), but what suits your hiking style and terrain. If you just want more traction, get longer points, but be aware of the trade offs. If you want good traction but are willing to forgo some traction for speed, then Microspikes may be for you. I like the faster descent and control I get with Microspikes and I am concerned that with longer points I would have problem with dragging, snagging and tripping--as with conventional crampons. I don't mind needing to use better technique to get traction when ascending or descending, so the shorter spikes are my choice. I know when Microspikes are not adequate, and that is when I put on my old faithful Grivel G-10s.
Recognizing it might be apples and oranges, here's what I switched to a couple of winters ago. From older, much heavier, SMC crampons.
http://kahtoola.com/product/kts-steel-hiking-crampon/
Light weight, goes onto boots in a few seconds each - just shove the toe into the nylon cage, pull up the heel and 'click'.
These come in a slightly less expensive aluminum version that weighs a few ounces less, and a product similar to the Hillsounds.
I like how these crampons slide down to a small, compact size when not on the boot and the excellent customer service Kahtoola offers.
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