I enjoy the comfort and power I get from playing with a full gut stringjob. However, lately, after changing to a racquet with an 18x20 string pattern I've noticed a drop in my spin. I don't hit with much topspin so thats no concern. Where I've noticed the difference is with my serve. Mainly my slice serve. I'd like to try out a hybrid using an 18 gauge in the mains and my normal gut in the crosses. What 18 gauge string could I use in the mains that would cause the least ammount of difference in comfort and power from a full gut stringjob. Thanks.