My experience was the complete opposite of the majority of reviews here, which had me terrified after initially booking my reservation. I arrived in Vegas on a Sunday night and was pleasantly surprised to see absolutely no line. Josh greeted me with a smile and efficiently got me thru the process while making casual, friendly conversation. There was zero attempt at an up-sell on insurance and I was out of there within 10 minutes. The return process was just as easy and just as friendly.
Would I have been frustrated with a lengthy line and less than friendly service? Absolutely. But I think you need to understand that if you book a deal and it's on a peak day at a peak time, that a thousand other people did the same exact thing. Consider it, and consider how slammed those employees are. Be kind! Cheers Vegas.