Ragatz re Grand Spey & 10151-4
With my terrible casting abilities, I'm probably the worse one to talk about my experiences with my brown 10151. With that disclaimer, here are my results with this rod and the GS's.
Early this spring, I spent the better part of a day trying Simon's test GS's with this rod. All three were floating lines. I used a Rio 10' Bone Fish Leader with 13.2 lb test at the tip. I tied a perfection loop in this leader and added 3 foot of 10 # tippet. I casted size 2, 4 and 6 sinking steelhead flies.
The river was running very high and fast and I could not wade out very far and had a high bank behind me which prevented a good long D loop.
GS 8/9 actually worked best with the rod. I hit the opposite bank about 80 90 feet, fairly consistently. The rod loaded and casted the line fairly easy.
GS9/10 for some reason with me was terrible. I could never get the rod to load for either the Double or Single Spey. It did worse of the three lines. It/I had a real problem getting the line off of the water.
GS10/11 if everything was timed right by me, I got some good casts and hit the opposite bank a few time, but this was less than with the GW8/9. Also, I was not as consistent with this line as with the GS 8/9. It required more effort to cast. Also, I had to strip in about 15' of line to get to the proper spot and then shoot that line on each cast to get to where I cast with the 8/9 with no stripping or shooting.
With this rod I have found with my 9/10 Accelerator and sinking tips, that I can cast it better removing tip #2 as well as tip #1 and attaching the sinking tips to the shooting body section.
These experiences make me wonder if the brown 10151 might be closer to a 9 weight than a 10 weight, at least in my inept hands.