The 48X approved Verbatim Datalife Plus found at Sam's club is indeed Mitsubishi Chemicals. It is using the super Azo dye, which looks comparable to other cyanine dyes (a bland blue, almost greyish). These discs have worked great for me, and they are very cheap at most stores (15$ for a 50 spindle, 24$ for 100).
There are also some Datalife plus's sold at Sam's club that are colored on the top label, and rated up to 32X, that are using the Metal Azo dye, which is a really dark blue, and much cooler in my opinion. They come in 50 packs with colored slim jewel cases. I have had terrific results with these discs. If they are around the same price, I'd opt for the latter.
Liteon 52x32x52 Black