Bock means it is a strong lager, slightly sweet, and has been specially handled to increase the alcohol (7.7abv) and flavor. Because it is a Bavarian brew, of course it is Reinheitsgebot compliant, and of course delicious. You "Must Have It."
The 0.5 liter (16.9 oz.) beer costs $3.49 at the Pangea Bottle Shop. If you haven't been there, go. You can read a review of Pangea Two Brews Cafe in general on this blog. It rocks. Don't be put off by the fact that this is one of the lower priced beers there. It is one hell of a value....
"Weizen": Like most unfiltered Weizen (aka Weiss in parts of Germany) it has a nice creamy golden color. The beer has a rich head and balanced carbonation. Like most wheat beers the hops are super subtle, and mostly used to balance the natural sweetness of the wheat brew and leave a relatively crisp aftertaste. It has a bready and full body, yet finishes rather light. These are traditional features of a good "Wheat" beer, and they are evident in spades here. Where Vitus really kicks ass is on the "Bock" side of things.
"Bock": I believe Bocks are the answer to people who say that German beers are too smooth or boring. They have obviously never tried a good bock. I am not saying all bocks are great, there are many Maibocks that I think miss the mark. However, when the strong alcohol and flavor of bocks is married to the rich smoothness of wheat beer, the results are usually startling good. Vitus has a wonderful aroma, with banana and cinnamon notes (mild), over a balanced malt. The flavors are so well balanced that it becomes a beautiful mix best described as complex (how else can the mouth bridge the range from chocolate to fruit flavors).
The Drink: The result is a wonderfully drinkable beer with full flavor and body, but no malty rotten aftertaste (my problem with some bocks). At 7.7abv, this is a dangerous sessioning beer. But with such a rich yet smooth taste, you may want to. The heavy alcohol taste does come out midway through the drinking, but you might be too tossed to care by that point.
The Review: First this beer is a great value that keeps pace with beers 5x as costly. Overall though, this is the best of two great beer worlds, and will surprise many people who avoid this type of beer on principle. For people who don't like bland wheat beers this one is complex, strong and rich. For those of you who don't like messy bocks, this one is well balanced, smooth and finishes rather crisp (for a 7.7abv brew). And, if you don't like either, well.... more for me!
Also try: Aventinus, a similarly excellent brew produced by Weiss & Sohns, Munich based makers of Schneider Weiss (an incredible wheat beer, one of the best!).