Strengths: If you can stomach the consistency, I've found these the best performing gels I've used. Flavours all seem to be good.
Weaknesses: The packet shap makes them hard to store on a run. Would prefer a long and thin shape so I could use a gel belt. Are very gloopy and thick - if you are dehydrated you will struggle to swallow.
Overall: If I'm running a marathon in cold/cool conditions always use these gels with water.