The real question is not which one is best. I see it as which one can you find.
Maybe it is just me, but there seems to be less 60 size plane on the market...
I think a lot of glow engines were made before .60s came along. But, you are right that 60 size models seem to be less available now than in the past. The primary glow model market seems to be...
40 size
120+ (and a lot of these end up with gasoline engines)
the 60 got left behind, and it is my favorite with a 91 four stroke up front