Should i buy a cassette based on lab test's?

I am a avid analog taper (cassettes)and i came across some cassette tape comparison articles from 1975 1977 1978 1980 1982 1985 1988 1990 and the last from 1993 and all of these test comparisons put TDK as the best chrome tape starting in 1977-1993 (TDK SA-X 1982 on).Is the TDK SA-X cassette the best high bias tape ever made or should these test's be taken with a grain of salt?I always thought the Maxell XLII-S tape was a good tape but all these tests put the TDK SA-X way ahead of the Maxell XLII-S tape and all others in the type II high bias catagory.What's your take on these test's,i would be curious to know what other's that still tape to cassette think?Thanks for any input,Keith H.
I use the Maxell and have tried the TDK. I thought that the Maxell reproduced further extended highs and tighter, cleaner bass. You may want to try one of the TDK tapes on your recordings equipment and compare the sound of the two on your playback equipment. That's always the best test.
And the only difference i can hear is that the TDK is alot more trebly (Brighter in the high end)which i don't really know if that's a better thing,maybe that's why the TDK SA-X always seem to better the others in tests,because it's a little hotter in the high frequency's making it spec out a little better...Keith H.
For all we know, they may have tinkered with the formulas for those tapes in the intervening years, so I wouldn't put too much faith in those old tests. On the other hand, high frequency rolloff is a problem with cassettes, so a tape that's a bit hotter up top probably is better.

One trick from the old days was to tape some white noise (interstation noise from a tuner worked well) on various tapes, and compare each to the original noise. Nowadays a pink noise segment from a test CD might be just the ticket.
You should find out what brand of cassette tape your deck was biased (fine-tuned) with. This should be your tape of choice as its parameters have been "maximized" with your deck. Of course, however, if you have a bias fine adjust capablility on your deck then it should be fairly easy to get good results with most tape brands.
Combine Bomarc's and Timo's response and you've got your answer. They covered different aspects of tape selection i.e. pre-adjusted bias levels vs machines with adjustable bias. Obviously, adjustable bias has advantages so long as one has a way of making sure that it is optimized for the given formulation being used. I think that the most advanced "auto-biasing" machines made came from Phase Linear / Pioneer. Sean
The TDK SA-X does seem to have a bit better dynamic range than the Maxell XLII-S and better high end response,My deck has both Bias and sensitivity level controls and i noticed that when both tapes are calibrated correctly,playing back both tapes at the same recording level and the same amp volume level with the same song the TDK lights up the low level frequency LED on my DBX sub-harmonic synthesizer and the Maxell does not which also shows the TDK's low freq prowess over the Maxell...Thanks for all the answers..Keith.