A question concerning the spacer frame:
Since it's an additional piece of hardware it's an additional potential point of failure.

I tend to carry my N900 in my Jeans' side pocket which is rather tight (at least if you put a 2cm brick in it).
So far my N900 managed the stress (primarily pressure and sheer force) without any problems.
I'm no expert in materials science at all, so could someone please give an estimate on how the spacer frame might react to the same treatment, with respect to its material, shape (thin ring of plastic?) and mounting points?