Here is a test response from one of my guys as well:
Configuration # 2
As with the first configuration, the experience was similar but slightly more intense, because the outer band increases pressure on the area of the penis which passes through it. Using the same size diameter liner only increases the very slightly. I first tried the same size dia. liner and band. I was pleased with the increased stimulation over configuration # 1, however, I thought it could be better. Considering I use a 2.25 liner, for my second attempt I used a 2.12 dia. as the band material with better results which were divine. What is nice with this configuration is that you can vary the experience by moving the outer ban up or down the length of the tube which changes the time and distance which it travels l along the shaft. You can set it high to concentrate on the glands area or lower to travel the entire length or even half way down.
Configuration # 3
In one word, “intense” describes this configuration. It was too intense generally for my tastes. It was very workable but I had occasional problems maintaining a seal during the test. I did notice after the test, dark linear lines on the head and shaft where the nubs were located on the clear liner. This was only a temporary superficial condition which disappeared after 30 minutes. If the nubs were a bit larger softer and a skosh lower this would rate the highest mark in my book if there was no sealing issues.