I used the Maurten 160 for both CIM and Twin Cities. I took Spring gels at both marathons too. I really like the Spring gels b/c they are thinner than other gels and go down easier (for me). I did find that alternating between water and the Maurten helped to cut the sweetness. I also mixed my bottles to have more or less Maurten concentrations. As other people noted, it’s all about experimenting during long runs and long run workouts. If you can’t get something from Ian’s store, I’ve found that The Feed is good for ordering single servings which makes for more affordable testing! 
Happy fueling!
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