I've been to this location a few times over the years dating back to high school. I used to come for the food (Texas toast sandwiches, tater tots, and breakfast burritos were most notable), but I only recently started re-visiting for their slushes.
A friend of mine suggested coming here during one particularly hot day a couple summers ago. It was Happy Hour (2-5pm) and that meant drinks and slushes were 1/2 off. I followed his lead and ordered a medium Real Fruit Strawberry and Lime Slush - I was hooked! I believe the medium is 16 oz and it was only $1 and some change! The only variation I've gotten is Strawberry with Pineapple, but I'm stuck on the real fruit. It's really delicious (albeit sweet) and I highly recommend it! Also, the large size is HUGE and only 40 cents more - definitely something to share.
Service has always been pleasant. I primarily utilize the drive-thru and have used the drive-up a couple times. Also, there's never a long wait.