This is a pure newbie question

When I add fenders/racks to my LHT, will I notice a difference in bike handling due to the weight? I've noted that Surly racks do seem to be heavy....is there a lighter-weight choice that would give me the same benefit? I know that Surly racks are pretty much bomb-proof...

I just do not see myself doing full heavy touring, though I can see light/credit card touring in my future, along with commuting and the odd errands. I was looking at the Ortlieb front panniers that someone posted on another thread here that she puts on the back of her bike - and was pleased to see that they make carrying straps for it so one can take it off the bike/into the store.

As far as loads are concerned, I would imagine that would be determined by how much weight one loaded. Just trying to get an idea what to expect when I start putting other things on my beautiful LHT.