Not sure what went wrong for these other Yelpers but I've been here several times to mail packages and have never had a bad experience. There's never been a line so I'm in and out of the UPS Store very quickly. It's located on the SE corner of Dobson and Baseline, same plaza as the grocery store.
Customer service has been satisfactory. I always ask about the cheapest mailing option and the second cheapest, and associated ship times (although I almost always go with the least expensive option). I've never received any attitude from the employees when asking these questions. Everyone has been helpful and quick to complete the transaction.
If your package isn't sealed, it's an extra $1 for them to tape it up according to a sign on the cash register. I don't review my receipts but I'm not sure I'm always charged this extra fee. Either way, it's only $1 so I wouldn't really be upset if I had to pay for it.