questions about tubes - to experts


I'm new in tubes (just recently bought first tube component ever), so I have some questions. I discovered Electro Harmonics company, how good are their tubes ?
Much worse them the best from what I had read here on Audiogon Western Electric, better them Sylvania, Swietlana... ?
For example is EH 300B worse them a few time more expensive Western Electric 300B ?
What is a difference between NIB pair of WE 350B and pair of WE 350B ? What NIB stands for ?
sorlowski
Sorry for the confusion, N.I.B. stands for {"New In Box"}

Is that better Gunbei??? ;0)~
I presume you're talking about 300B tubes? If so, I know nothing about EHs as have always used Western Electric. But I'm considering getting some Sophias just for fun - maybe the new Princesses.