Does anyone use these and is the difference significant over standard rods? Is there increased stress on guide foot in heavier techniques such as flipping, t-rig, c-rig, deep cranking that may cause breakage?

I build spiral wrapped rods. The truth is that you are less likely to break the rod blank under heavy load because the rod is not torquing and twisting. With eyes on top, physics dictate that the rod would rotate to eyes on bottom. Your wrist and grip forced the rod to keep eyes up so the torque builds. Not sure it is that big of a deal, but it is better for the blank in terms of longevity.

I have used them. When trying to pitch it is harder for me seems like the line does not come out as smooth. My wife still uses them for crankbaits and spinner baits and like them.

I have 15 made by Dave Settle of Custom Angle Rods at Lake Fork. Very well made, light, very sensitive and cast very well. I've never had one break during use....broke one putting into rod box once. My bad!

Big difference vs conventional? Could I tell the difference blindfolded....probably not!

Dave's personal input into which blank vs what you're going to use it for is the biggest value to me!