After shopping around (and having the Lite-On, LG, Samsung and Having recently purchased an LG BH10LS30.AUAR internal SATA 10x BD-RE drive, I decided to go shopping for some writeable media. I was almost preparing to buy some bargain basement BD-Rs before reconsidering (and reading some less than glowing reviews of data become progressively corrupted after just one year, slow and variable burn times, many burns ending in coasters) -- it reminded me of those halcyon days of 4x external USB CD rewriters! I couldn't justify the cost of very pricey Verbatim media, at least not without any peer reviews, so I went for the middle ground.
Anyway, given that TDK have produced their own BD-R media for a while now, I decided to plump down a few units of my local currency and purchase a ten-cake of some TDK 4x 25 GB BD-Rs (part number t78088, I paid £16.15 on the 7th of September and they're currently at £16.84). I'll shortly be doing a test burn with some mixed media and will duly report back with qualitative burn analysis, some general read/write speed observations and any other findings as to the quality of the discs themselves.
UK blank media e/retailers: if you'd like to send me test media for review please get in touch, I'm considering making a miniseries of this due to the absence of decent like-for-like comparisons of currently available blank BD media.