These seem like killer options, and I personally think the Zen dac is awesome for what it has. Really something people should consider if they are looking for a dac, or a light dac amp balanced combo. And it has balanced headphone and pre out as well which is crazy for the price
The Zen Blue looks great for the price if you want streaming and wireless, so something else to look into, but the Zen dac seems higher quality to me if you only care about the dac.
These are both $129 USD which is really good for the price (I believe)
I will have to check out both of these in person when I get the chance