Does anyone know if the Airflo 40 plus in an intermediate, is any good for Stillwater trout fishing with a switch rod? I need a line for overhead casting and I can't find any reviews on it. I would also like to know if it will really cast 35 to 40 yards with two false casts like their YouTube video advertises.
The concept of the 40+ is pretty simple: it packs they weight of a long, distance taper line into a short head design and then backs it up with lots of running line - total 120'. So the length and the weight is there if you need it.
This results in a line that is about two line weights heavy compared to an AFTMA chart, but then the total head of a distance taper line is also at least two line weights heavy, if not a whole lot more. The weight of the entire head of a typical distance taper, AFTMA accurate 5 wt. can be close to the AFTMA rating for a 10 wt.
So can this line go far? Yes, in the right hands. Before my elbow troubles, I had no problems casting the 10 wt. coldwater salt version and a big clouser about a 100' on my 9' 10 wt. saltie rod. I used a Spey setup cast, water loading into one backcast, slip some line backwards and then send it on its way. (and no, my elbow troubles weren't related to this

).
I used this approach as stripers can hit close in so we strip a lot of the head into the guides. The end of the head can finish up in the stripping basket. The Spey cast got the head out of the guides and the water load let me fire the line out quickly with no false casting - don't like false casting heavily weighted clousers.
The front taper of a 40+ is quite long so it will roll out nice and gentle if the cast is allowed to run out of gas. It's really a shooting head with integrated running line so whether it presents gently or not depends on how it's handled.
I use a 9 wt. 40+ Expert line (longer front and rear tapers) in an intermediate on my 9 wt. PRO 4X switch rod as a cold water line for this rod. Works fine. The Expert might be a better choice if you're very worried about presentation.