[sdiy] brand names

[Stephen Begin]

I was wondering if there is a big difference between different brand names
in terms of the overall quality of the part.  I'm looking at zener diodes on
mouser and you can pay 40 % for central semiconductors over rectron or
vishay-telefunken diodes of the same series.
I wasn't sure if in components "you get what you pay for" is a good rule to
follow or not.
Is the difference between say a 1n4700 and a 1n5200 also a quality issue or
is this more related to properties of the diodes that may be essential to
certain circuits but make no difference in others?
Thanks a lot
Steve