The gullet helps hold the file at the proper height to set the side plate angle/the hook. If you remove the gullet first on a newer chin then you will have to constantly hold the file up against the top plate.
That being said, you do need to remove a very small portion of the back of the gullet, but not as low as I clean them up when done filing the cutter unless you are further into the life of s chain.
I like them a lot, and I use them on chains that I get that someone thought getting the gullet hogged out was going to make their saw cut faster, it holds the file up onto the cutter nicely.
I've never had a chain last that long, I filed one this week down from 80% to 10%(if you stop at the witness marks), but I had to flush cut a bunch of stumps. Only touched it up once while cutting the trees down and limbing them, cottonwood and couple pine so it was softer wood.
That's great you had someone to stand beside and learn.
Waiting to here about he shared
.
It's funny when you watch a video on how to use the roller guide and then when it comes time to do the rakers they set it aside
. What they don't realize is how well they work for setting them to the proper height. The stand alone version is a much easier tool to hold and they last much longer though.