I just got back last night from 3 days in Yellowstone doing some end of the season poking around the Lamar Valley. I had the new 115MM which arrived the day we left and the 95MM so we were able to do a side by side. We were able to go back and forth between the 2. My wife has very high expectations for optics and was going to end up with whichever was clearly better. Just jumping to the answer - she is indifferent between the 2. A few observations.
1. The 115 is huge. Makes you think the 95mm might be an 85mm. Also - barely fit in my bag that holds both the 95mm and the 115mm lens with ATX and STX. I will need to find a new bag really.
2. The 115 is heavy. VERY heavy. It is front heavy. It needs a balance rail. The Swavorski it intended to be adjusting for rear weight of BX or Digiscope - so I ordered the outdoorsman - hoping that helps. I was basically overloading my Sirui VA-5. It might send me up to a Benro 26 or similar. Also - I ended up removing the center column and direct mounting on my Sirui R3213-x tripod (which is a bit like the 3204 but fewer legs).
3. The optics performance seems identical between the 2, in almost ever situation. Throughout the day, in good to decent light, really all of the way to sunset they were indistinguishable. There may be a way to measure with instruments it but we could not find an advantage - including tracking a grizzly deeply into the shadows of the woods. We assumed that after sunset there would be a huge difference. There really was not initially. It was not until it was 30 minutes plus past sunset is where the advantage showed up. The one place it really showed up was near dark AND zoomed in. Once we got to 50 - 70X it was noticeable. Basically 50X on the 155M looked like 30X on the 95M. I also made me wonder if there was more opportunities for difference with DSLR digiscoping in lens resolution.
Just some thoughts. It make you appreciate how great the 95MM is. Glad we have the 115MM but I don't think we will sell the other 95MM to get a second 115MM. In fact were were more wishing we had a 65MM for some hiking we did.