roger lance
They are different alright....differently made....differently sized....etc. Both are extremely flat.

I'd also suggest shopping at your local WoodCraft.....they have the DMT line.....you can inspect what you are buying.....have it taken out of the packaging and give it a good going over for flatness, etc. WoodCraft has their sales.....15% off and other promotions.....its possible to buy a Dia-Sharp stone for less than $56 which will include local sales tax.

Decisions....decisions.