It's definitely not a nightmare... The place is always freshly cleaned and whatever lines they have always move quickly. I'll usually stop for $0.99/20lb ice or coffee or gas or maybe a breakfast taco or brisket sandwich. Generally, quick in/out.
On some days, i.e. holiday weekends, it can be pretty crowded, but they are experts at moving many people.... that said, I usually avoid those days since I'm trying to get to my destination without delay...