Ignoring any issues of firmware compatibility (i.e., what model of drive do you have?), then these are good discs: YES.
Media ID for 4x 50GB Panasonic BD-R = MEI-T02-001
MEI = Matsushita Electric Industrial
Matsushita = Panasonic + JVC parent corporation, which is why you find them in Panasonic branded packages.
Amazon has a 50-pack for $350:
http://www.amazon.com/gp/product/B00...SIN=B00406VZ40
How does this price compare to what you've seen?
A new review dedicated to Blu-ray quality (BD-R, BD-RE) is currently being written, based on a year worth of testing. More guides are being written to address complementary concepts of longevity, burning, authoring, etc. It will be completed by the end of February, though I hope to have it completed much quicker than that. Just have to be realistic about timeframes, given all the projects and other guides/editorials currently in the queue. You should see some major changes to our media articles soon. I was penning outlines this afternoon, going over the new layout of information.