In case anyone is interested, I've posted a complete review comparing WundrBars to Twennybars: https://np.reddit.com/r/soylent/comments/5gbaxv/wundrbar_vs_twennybar_review_pics_inside/
If you just wanna see some photos: https://imgur.com/a/or0wb
I like it! I think it's a good product on its own, though the flavours might be too strong for my taste, especially when compared with the quite neutral Chocolate Twennybar. Nutrition-wise I like it better due to the reduced sugar and increased protein contents. Texture-wise they are very different: both are dense, but WundrBars are dry and hard, whereas Twennybars are more spongy, and I think both have their charms.
However, just like the Twennybars, the WundrBars are way more expensive than their powdered counterparts, and it seems that even if they were cheaper, one could not solely rely on them due to their potential laxative effect. As Queal says it:
You can replace any meal with a WundrBar, but not every meal.
I will continue to buy both WundrBars and Twennybars as occasional meal replacement/supplement, since I think both have their strengths and I do not think one completely blows away the other by any means.