telescopic stocks: any good?

[fred]

I'm not a fan of the Knoxx Stock. It seemed to cause many of our troops to short-stroke. I put many rounds through them before going back to our Remington PG stocks. Also, they broke quickly. I would definitely sample some before spending $$$.
I have no experience with the Mesa Tactical stocks, but I can enthusiastically recommend Mesa Tactical as a great company to deal with. They are awesome.

[Gutshot John]

It seemed to cause many of our troops to short-stroke.

I don't dispute anything you said, I'm just curious what causes the short-stroke?

In my experience short-stroking is more of a training issue/operator error, but I'd be curious if you'd elaborate if there is a mechanical problem that effects this or elaborate further.