Go with low expectations. Yoshi's is the poor man's sushi, and what you get, it's pretty good. There are many better sushi places, but also consider how much more expensive they are based on the quality. Yoshi's still provides a decent meal with a bit of variety and you won't feel like you're getting sushi from a fast food place.
I recommend sticking to the sushi rolls. You can get a fair amount for pretty cheap. It's also not very crowded, and I've been there multiple occasions for a quick bite. I've never experienced any problems with service.
Staff is friendly.
Parking is easy.