You should try the disc sander before knocking it. Best part s there is no jig to worry about. Its just a block of wood - I just square the block on the disc, check with a machinist's square, clamp and go - it's worth setting up for just one joint. Another advantage is is the accuracy I can get with a cheap, compact tool. To check the table angle I square 3 edges of the block and check the last corner with a machinist's square for extreme accuracy. You need that kind of precision as any error in the scarf gets magnified by the scarf ratio and doubled again by the joint; a quarter degree will show up clearly.

Having said all that the next most convenient method that I used for a couple of years was the chop saw, but I found the jig deteriorated with use and I was continually rebuilding it. The disc sander is faster but the fastest method of all is probably a table saw with a jig that can handle multiple strips, but I don't have the space for floor tools.

Ultimately though this is going to end up like a political debate . . .