I bought a 10' 4wt TFO BVK a few months ago and really like it. I thought it would be a specialty rod, but I'm using it on many more stream conditions than I originally expected. I shopped around a bit for a long nymph fishing rod and ran into a couple of dead ends before buying the BVK. I'd watch out for rods that are too heavy or too tip heavy. Also watch out for rods that really soft into the mid-section.

I haven't cast a Sage One, but I suspect you'll like it. It sounds like it's light and fast action which is what I wanted. But it was too expensive for me, so I opt'ed for the TFO BVK (which is almost as light and fast). I use a Lamson Velocity 1.5 on my 10' BVK.