Can't expect too much in Eugene, no less an "authentic" experience. We aren't in Mexico last I checked. I don't think any Mex. food here in the US is that authentic anyway and if it was, we'd probably not recognize it if it hit it in our face. Or we'd say that even THAT was not authentic.
Ok, so I thought the food was very tasty & fresh - had the shrimp fajitas. Best I've ever had and I've lived in NYC, LA and a few parts of the midwest. Ineside it is quirky, if not a little dumpy, but that was fine. We were just happy to find a decent Mexican place that doesn't look like a greasy sports bar dive.
The chips were cold though.
The rest well worth the money.
Also, I had a mango margarita and it was good - I'm not much of an alcoholic, so I can't really comment on the content - I drink them because they taste good not because I want to get buzzed off them. If that were the case I'd order a shot.
Other than that, service was very polite and very prompt.