Back in 1970's, I spoke with the man who made Linspeed and asked the difference between Linspeed and Tru-Oil. He said that Linspeed was linseed based while Tru-Oil was a varnish.

I like them both but Linspeed can be slow to dry, and sometimes never, on old wood. Tru-Oil dries faster but is not easily rubbed in because of that trait. I have often mixed them and regularly mix Tru-Oil with Tung oil varnishes.