I have an 11x14 Beseler, one of the older all black ones, and a Saunders 16x20, and I've used the Saunders 11x14 model.
The Beseler is quite good, and much heavier than the Saunders models.
The downside is that they are a little fussier to use, some paper sizes are held at the top of the paper, some at the bottom. On mine, the scales aren't accurately placed, and my Saunders is better in that respect.
I never have worked out the best way to get the frame, blades, and base all square to each other. The Saunders seems less prone for the frame to be out of square, but I've not had it very long so my evaluation might change. OTH the frame of the Beseler is much stiffer.
If you're are concerned about a getting a used, possibly tweeked Saunders, the Beseler is a good choice.