I agree, the B&K is a great tester, very simple to use and difficult to kill. If you select the wrong knobs on a big Hickok you can blow the transformer or damage a switch. I purchased a Hickok 752 last year and although it does a much more through job that my (now sold) B&K, I often miss the simplicity of the B&K.
My experience is the B&K is more likely to "fail" a good tube than "pass" a bad tube. Use a little caution on those marginal vintage tubes and allow them a few extra minutes to warm up before chucking them in the trash because they didn't test perfect.