Wheels - question

[Catrin]

I hope my question will make sense, I am unsure how to word this. The main reason I am getting the Gunnar Sport is to have something lighter and more responsive on club rides. That being said, because of my physical needs the frame I am considering is a more relaxed frame meant for long-distance riding. It is not, quite, the slacker frame that my LHT is, but it isn't a traditional roadie frame either.

My LHT has bomb-proof wheels and is as stable as can be. I am not using the bike for loaded touring and may never actually do more than light credit card touring with it. I do love the wheel-set however and love how stable it is.

Considering the wheel-set was built for use on a fully loaded touring bike and, probably, for someone heavier than I, I have a question. If I were to get a second set of wheels that were lighter and more appropriate for my style of riding, would I notice a significant difference in how the bike performs if I went with a skinner 26 inch tire? I do have rack and fenders on my LHT, but they don't weigh much at all...

If this would make a significant difference, then having two wheel-sets might be an interesting option....perhaps.