The only discs I have ever purchased that do not vary--not one bit--are Daxon AZ2, and they are rated 8x, but playback only when burned at 4x, and the scans are terrible--always really terrible scans that are barely within maximum DVD error tolerances. Data integrity is always 100% even when oversped to 16x. So, good-for-data may be a lot different than good-for-playback. Scans do not differ when burned at 2.4x, 4x, 8x, 12, and 16x. Weird stuff. Fantastic for backups, not great for movies. Given that this media makes the verification step unnecessary, waiting through a 4x burn for a movie might not be too bad. I was hoping for better.
CMC discs had the best (chances of) playback, but I had to put a very large amount of CMC media into the trash can because of data integrity issues--pretty scans, broken files. CMC's Philips C16 (BenQ 16) works fine at 16x, and is simply awesome when burned at 12x. 12x= under 6 minutes, low errors, 100% integrity. Their Philips media code is their premium make. So, I'm not exactly staying away from CMC, but I always perform a copy-back test on that media rather than a (fictional) scan. This is yet another media that is best when used under the rated speed (much less trouble). While CMC media code has high entertainment value, it is really useless (unsafe) for data backup.
Ritek has a nice combination of great playback with much less issues of data integrity. So far, Ritek is the winner. Errors at the end-of-disc may make for choppy playback at the end if these are oversped (10% coasters). But, they work just fine when used AT the rated speed. Kudos for Ritek!
This cheapskate is off to buy some Prodisc next to try them.