I love this dispenser, it is a little hard to clean out but it the best way to dispense your Gel. Buying the Gel by the larger container vs. the packets is really good way to save packaging, pay less for the gel and not cut your mouth on those metallic packets. Plus you can swallow a little or swallow alot and no messy packet to deal with later.
Have used several times on my training rides. I make my own GU. Issue for me is that it is not easy to use one-handed. Taking two hands presents some additional risks while cycling. Furthermore a few times the entire top rotated, vs just the spout. Thus I will continue to use on training rides but in other rides will likely continue to use the packets that I can open with my teeth.
Other than the hard-to-loosen nozzle, the other serious downside is if you don't work thru the batch in your flask relatively fast, then the gel hardens in the flask corners and along the bottom edge. Short window to work through 5 packs' worth. So back to the individual eco-insensitive packs I go ,)