We purchased ours from Discountmugs and had no issues with the screening. Perhaps it was just the type of mug that Heidi used - note also that her original post is not recent. It's quite possible they have fixed the problem since then.
Regarding the temperature - any two-walled mug design (whether it's interior is plastic or stainless) with a lid will keep a drink colder than a one-wall mug design. That being said, when it's almost 100 degrees outside, even the two-walled design can only do so much. The drinks will eventually warm up. The main reason we purchased the mugs for our guests was not so much for keeping the drinks cold (even though that's what we all put on our tags!), but for the size. A lot of AIs pour their drinks in small, disposable plastic glasses which means the drinks get warm really quickly, and they don't hold much, so you're making more trips to the bar! At Dreams they used glass instead of plastic, but our mugs were bigger so they obviously held more of the good stuff!
If I have any complaint, it's not about the logo rubbing off, but the sand scratching the shiny surface. However, this didn't bug me (or anyone else). I still use mine to hold my coffee every morning as I commute to work. My sister uses hers to hold drinks around her pool every summer. They were definitely worth the cost and trouble.
Here's a picture of ours: