IMHO, it's pretty ok stuff, if you're into beer. I drank it all night once when there wasn't anything else remotely resembling decent beer. As with most Shiner products, it's pretty bland, but it's quaffable in rather large quantities...and beware the hangover.
...and if you're ordering it at a bar, don't ask for "Shiner Helles," especially if you pronounce "helles" correctly. Just call it "Shiner 99."