Shapton lapping plates

I was wondering if anyone has compared the Shapton Glass Diamond Lapping Plate to the Shapton Diamond Reference Lapping Plate. Please comment

I spoke with Harrelson Stanley at Shapton USA today. For someone honing razors he advised using the glass diamond plate instead of the reference lapping plate. His explanation was that the glass diamond plate is the flatest and most precise of the three Shapton plates ( including the compact). It is also less messy since you are not using the diamond powder and water to do the cutting. The reference plate is more appropriate for lapping stones for use sharpening woodworking tools such as plane irons or chisels.