TDK all the way!
I tried many different brands, and although TDK was usually a little more costly than Maxell and not as readily available for me, I found them to me more consistent. From what I was told by techies at the time the "db scans" were more level and consistent than Maxell. I'm not sure what that actually meant, other than the understanding that they were more consistent. I never noticed a difference in noise, when comparing apples to apples, but generally found the "x" models to be quiet as hell. In other words, the SA-X and the MA-X were the quietest tapes I've ever used (SA-X being the best - but the MA-X offering unprecedented headroom). Another thing which came in handy was the extra tape. Maxell seemed more ridged on the amount of tape, whereas TDK gave about an extra minute...how many people using Maxell didn't get cut at the end of Gloria in Richmond, VA???