Bob, been a while since I seen an issue of either, but from what I remember Shopnotes is geared towards shop related articles, benches, storage, jigs, techniques, etc. Woodsmith leans toward projects, how to's, plans, finishes and stuff.
I used to get both before I trimmed down the number of subscriptions I was getting. Both, back then, were excellent publications. As I said, I haven't read either in several years.
Good Luck, Tony.