Recently, I bought something from a vendor recommended by someone here, and while the attention was pretty decent and prompt, there were a couple things missing: tracking number on shipping, and all questions answered.
One thing that addresses both of these was that I asked for a tracking number and the question wasn't even answered, let alone given a number. I'm not saying anyone here does this, but just to emphasise: both for reasons of assurance and to avoid general hassle, go the extra millimeter (or maybe centimeter) and provide a tracking number for items shipped.
In my case, though he said it'd be two days (um, yeah, okay), it turned out to be five. Then UPS didn't come to my door, so not even a note left, plus the office staff missed it in the pile the two times I went and asked if anything came. So, after a week goes by I'm bugging this guy about not getting it. Of course, not getting my questions answered made me a little suspicious, but I was convinced of at least the earlier reputability of this vendor that was conveyed by the person who recommended. I did finally pick up the items, and they appeared to be in excellent shape - but the affair was a little, unnecessarily, messy.