Permalyn-
The sealer is very thin and easy to work with. Different woods require different techniques/finish.
Maple is typically "tight" and just the application of Permalyn sealer can get the job done perfectly.
In my opinion, I like the wood to be sealed/finished right to the edge, meaning that the finish is not noticeably "built up" past the surface. Some people say that the finish is "In the wood", and it will give the stock an earthy and warm feel and look.
Walnut- Most slabs of walnut are typically more porous than the maple, so "in the wood" finishes will still have a multitude of tiny pores still visible at the right angles. The trick is to get it looking finished without going too light or too heavy. I have finished walnut with Permalyn sealer only, and have had great results with tighter old growth walnut.
I do not purchase Permalyn finish, just sealer now. Good stuff, and EXTREMELY weather resistant.
Tru Oil-
Tried and true, with natural oils and synthetic driers. Easy to repair, can be thinned readily, and is a classic tried and true finish.
Can be applied over Permalyn sealer, for a bombproof, easy to repair finish.
Tends to be quite thick, so take it easy on any finish coats with maple, walnut is not so sensitive. I would advise against getting Tru Oil built up very thick, where it appears that there is a "skin" of finish on top of the wood. Stop right at the surface, this lets the color impart a very nice hue, as it will not dry perfectly clear.
Tru Oil has a natural tone when dry, so this is a nice bonus when you go with natural oils.
Gloss or satin?
Tru Oil if built up naturally goes gloss, but can be taken back easily. Permalyn sealer if used correctly goes satin without any fuss.
Either finish works- You just have to use it correctly.
