I think that the AS350 with the floor window is one of the most comfortable platforms for Vertical reference work.
Have you tried a 407 with a bubble window? Now that's a comfortable Intermediate for VR work. All that you need for power info is one single "check instrument" light mounted outside and you have all your power parameters covered.
If you're on seismic, I believe that you could be one of the best 350 VR guys, but the facts are...most average joes who try it, never get good with the pacman window. They don't do enough and only get by.
I also agree, go big or go home, the longer line the better in a 350, or for that matter any aircraft. I was at 9,500' all day yesterday, not a tree in sight, but still used a 100', just because it makes the job go faster, safer and easier.