After using Clif Shot for 20+ years, I was forced to look elsewhere with the demise of that product. I had tried GU many years ago and was not crazy about it. But, decided to try again after reading other reviews. Chose vanilla for flavor and minimal caffeine, as too much can be a problem for my heart rate. I like the taste and the boost from the caffeine is effective without causing an issue. The consistency works for me as well. Not runny, but not chewy. Two gels on a 30 mile ride that takes an hour and fifteen minutes or so works out well. For me there's a seven to eight minute delay before I feel the boost. The Clif Shots seemed to work a little quicker, but this is not a deal breaker. My only issue with GU is no Litter Leash type packaging as Clif Shots had. If that was in place, then this would be a 5 star rating.
I mounted this to my MOG and it fits like the dream, tucks perfectly behind the stem and makes no contact with legs even when out of the saddle. I used it with a gel mix and it works great, but definitely best to be on the lower viscosity end (more water less solid). Holds strong even over gravel terrain. Only notes for consideration are that the bottle itself is $60, no thank you, so if you are doing epics where you sub in bottles that will be a deterrent. Also consider adding a piece of frame protectant where the bottle touches the frame, as it will wear the paint.
Did a 90 mile ride on a hot humid day and these bottles kept my electrolyte and carb drink cold long after my insulated podium bottles would have. Also, appreciate that I'm not worrying about the plastic leaching into my drinks on hot summer days. Couple caveats that made me lower to 4 stars. I needed new water bottle cages because one of the bottles popped out of the carbon cages over rough roads which are plentiful in New Jersey. Fortunatly the cheaper recycled cages worked well and I'm not worried about them popping out anymore. One of the stone colored bottles, which looked great when I got them, was scratched up pretty good when it came out on a ride and both are getting a little scratched up in the cages. Still look decent, but you're probably better getting the stainless steal. Overall, the fact that my drinks stay cold made them worth the buy.
I only use these on long rides of 25 miles or more (which is increasingly rarer as I get older). They provide a quick energy replenishment for long, slow rides without the bulk. One energy gel every 45 minutes seems to be the optimal consumption cycle and with the variety pack, you don't get tired of the same flavor say during a century ride.
I like to squeeze out the remainder of the gel between my teeth and therein lies a lesson: fold it in half, otherwise as I painfully discovered when I cut each side of my lips with the edge of the packaging. A painful lesson that no one should every repeat.
