Thank you for the post. I have sent 2 orders (a total of 81 cards) to GMA and like you I received both back within 10 days. Like you these were PC cards and not high value ones. However, since I like the graded card look (though don't own many and often out of budget) I gave GMA a try.
I am very pleased with the results I have had so far. The service can't be beat for encapsulating cards, pricing is fair, grading seems decent and the case/label are nice. I will be sending more to them in the future as well. As far as later return value, these are cards I'm not really looking to move and I figure if they look alright to me, that works! If I had high value cards, I'm not sure I would send GMA based on potential monetary value, but for everything else I'm in.
Between my 2 orders, there was really only one small item I noted. The horizontal view cards were inserted into holders in different ways. As you hold the card to view, sometimes the label was on the left and on next card had the label to right. I know it's a small item, but did stick out to me.
Anyhow, Glad to hear there are others as pleased with GMA as I have been so far.