Strengths: Easy to open and store in bum bag. I was warned that you get a bit of a horrible taste and you should wash them down with water, but I never had any problems. Quite nice in fact
Weaknesses: Not too keen on the tropical flavour, but that's a matter of taste.
Overall: First year running properly, I had Snowdonia marathon coming up and a friend advised me to use gel packs, I had never heard of them before. I got two, the blackcurrant and the tropical, took them at 13 and 19 mile marks, what a difference they made. I just wished I knew about them when I was doing my training runs.