For hone master's

It's pretty expensive, but I love the Shapton DGLP....love it.

If I did a lot of honing and lapping I would definitely get the shapton flattening plate. I don't have one but got to play with one and it makes lapping a breeze. There is one other thing that might be better but haven't seen it here which is a large brick like looking plate of ceramic with grooves on which you throw some aluminum oxide and get to work. A video I saw flattened a stone in like a minute flat and there was literally slurry bleeding from the stone, I mean like severed jugular type bleeding, kill bill movies aint got nothing.

The thing about the GDLP, aside from the excellent design, is that there is no flattening plate/stone as close to dead flat as it is. Except maybe the Shapton DRLP. For the perfectionists among us. :)

I've used both and unless you need to flatten planes and chisels and such there is no advantage to the DRLP. I personally have no need for the reference plate. I wouldn't refuse a free one, but the DGLP is so close to it for what we do it's not worth twice the price IMO.