To the OP: Thanks for posting the question! I've been thinking about using different kinds of wood, but its been on the back burner for quite a while.
I've only used JD barrel chips so far.
There are several "reports" about bourbon makers using maple barrels, but I'm skeptical they are using actual barrels.
Barrels made from maple are prone to leak.
A commercial distillery won't tolerate their product leaking away.
I believe the distilleries that say they are using maple barrels are actually using toasted maple staves in a tank.
I'm probably wrong about the above, its just a theory, but one based on logic and experience. Years ago, I was in the lumber business and sold white oak to a barrel mill. I never heard of them buying any maple for their barrels.
I also looked around for any barrel producers /re-sellers that had maple barrels available, and I can't find any.
Their are many types of maple trees, usually divided into two groups: hard maple and soft maple. Note that soft maple wood isn't soft, its just not as hard as hard maple.
Hard maple is what is usually used to make maple syrup, although you can use the sap from soft maple trees as well, it just won't have as high a sugar content.
Hunting around for information, I came across this gem, a brew club did an experiment where beer was aged on different wood, great stuff:
http://www.nordeastbrewersalliance....ments/2016-experiments/wood-aging-experiment/
Apparently there is a difference in the flavors supplied by hard and soft maple.
If you want a butterscotch flavor, it looks like yellow birch will supply that.
If you want to use your own wood, note that barrel makers season their wood outdoors for 2 years before making a barrel. If you use kiln dried wood available to wood workers you'll get a different result.
If you try to season wood like birch or maple outside (uncovered in the weather) its going to rot, so keep it under cover during seasoning.
I don't usually drink whiskey, but I'm going to use the information in the above experiment in future beer, cider and mead projects.
Articles about research regarding whiskey and wood:
https://www.scientificamerican.com/article/whiskey-makers-break-tradition-to-make-new-flavors/
https://www.thedailybeast.com/extreme-whiskey-barrel-aging?ref=scroll