SUPER sweet
Generally not very sensitive to flavors with this kind of stuff but I find it incredibly sweet if used in the full 2-scoop serving (and my bottles are even bigger than the 500ml suggested).  Can't argue against it's benefits as it seems to work pretty well and the nutritional facts hit the right amounts.  On very long/high effort rides I occasionally go with the full serving, but I highly recommend balancing out your other fueling with something salty/sour to neutralize the sweetness.
Rating: 4 stars