I have used Allegro on a workstation (UNIX) for a little more than 4 years, 
and my brother used
PADS.  I think the decision for one or the other depends upon the complexity 
of your pc boards.
I have designed very complex pc boards using Cadence's Allegro product and 
have never en-
countered an obstacle that could not be overcome.  The ease of use and short 
learning curve
of the Allegro product is a definite plus.  I went to a demonstration of the 
PC Based (Windows)
Allegro product, and it seemed to have everything, if not more capability, 
than the workstation
based application.  On the downside of Allegro, Cadence does not like you to 
have third party
integration into their database, you can extract all sorts of information and 
modify it to your
hearts content to interface with another application, but Cadence would prefer 
if you used their
own application (for example: Autorouters etc.)  I had no problem with the 
Cooper & Chyan
CCT autorouter interface to Allegro though.  CCT has made the translation 
pretty seamless.
As far as PADs goes, In my own opinion of course, it is not made to do 
extremely complicated
designs (although I have seen some designs like that done on PADS)  I think it 
would be easier
to do on Allegro.
by the way, I am using Mentor Graphics now for the last 2 months,  and I wish 
I was Using
Cadence Allegro!!!       Hope this helps you, you can contact me directly if 
you like for further
clarification.
(708) 898-4596 x346

Karl Bates
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