Does the type and flexibility of metal used in guide feet and frames have a measurable, or "feelable" difference on a completed rod? I'm talking about lightweight rods, not big game saltwater rods.

Phil,
I have no idea what the words in your question refer to.

A guide is a guide is a guide.

A guide that is heavier than a different guide weighs more.

A guide that is lighter than a different guide weighs less.

Guides under normal fishing conditions do not flex.

Good luck

The weight of the guide has a greater effect than the guide's ability to flex with the rod. But flexibility is desirable from other standpoints.

And no, stiffer guides do not stiffen a rod - all guides end up softening the rod due to the added weight.

.......

The reason I ask is I have built a few fly rods in the 3wt. to 5wt. range using REC "light" (thin wire) TiCr snake guides, which are very flexible. [I use a couple of Forhan wraps to keep the guide feet from backing out from under the thread wraps.] Several accomplished fly casters prefer these rods to rods built with chrome-plated steel guides, even though they won't be subject to salt water.

Phil,
You indicated that some folks prefer the REC guides over standard steel guides.

Do you know the reason why the folks prefer these guides over standard steel guides?

Roger, are you not asking Phil the same question that he is asking? He notices that accomplished casters like the rods with the REC guides better and is trying figure out why.

They allow the rod to flex more naturally and are lighter than standard plated snakes so there is a different feel. I never use a locking wrap on double footed snake guides and have used REC light on many rods without issues.