I have been using for a while these gels as my energy source during long competitions, especially in the marathon. It is composed mainly of a mixture of maltodextrin and water, plus some preservatives and gelling agents, and acesulfame as sweetener.
The nutritional information is:
Per 100mL: 144kcal / 0g fat / 36g carbohydrates (of which sugars 1g) / 0g proteins / 0.01g salt
Per gel (60mL): 87kcal / 0g fat / 22g carbohydrates (of which sugars 0.6g) / 0g proteins / 0.01g salt
In the instructions it is said that you can take up to 3 gels per hour, without the need to consume water with them. For me this is one of their main advantages, as during races I don’t have to worry about the next water station to take one, as it happens with other commercial brands.
I usually take 5 gels for a marathon, first one in the kilometre 12, and then one every 6 kilometres: 18, 24, 30 and 36. That is roughly one every 30-35 minutes from the first hour (for a marathon time between 3.30 and 4.00), a bit under the recommended dosage, but I find difficult to carry more gels with me. Each 60 millilitres gel provides 22 grams of carbohydrates. That would give about 40 grams per exercise hour. You can also try consuming them for shorter distances.
Depending of your needs, buying in bulk can save you some money, as prices may vary between 1 and 2€ per gel. There are packages from 6 to 30, and selection boxes with different flavours that can be a good choice to get a taste, although I usually go for the orange one, as I am not particularly fond of the other choices. There are also caffeinated versions, if you want to try that extra edge.
Score: 5 (out of 5)
Pros: no need of water; texture; package resistance (not the first time a gel broke in the pocket) and opening ease.
Cons: not really, besides my own distaste of some flavour combinations in gels (blackcurrant for example).