Favorite 5-weight lines for mending?

I'm just full of questions lately.

I was out fishing today with a 3-weight Sylk line (as opposed to my
usual 5-weight SA GPX WF)... and suddenly, I could mend just like I've
read about. Picked up the line, mended, maybe even twice -- all
without my dry fly moving a millimeter. Amazing!

Normally when I mend with the SA 5 GPX, I get a nice little pull on my
fly for a second. (Nice, meaning, bad.) Maybe it's my poor technique.
Probably. But the fact that it worked so easy with the light Sylk
like has me wondering. Anyone have any particular lines they like for
mending - talking 5-weight, trout-fishing here? (I know that DT mends
better than WF, at least that's what I've read. Just wondering, I
don't know, how much difference it makes, or if some lines are
significantly better than others outside of WF vs. DT, etc.)

For the record - I think I'm generally pretty good about keeping my
line clean. So I don't think that should be an issue...

Thanks as always for your insights, Tim