Re: altium, protel, pcad
hi
if you are using orcad tool then it is good to use. As far as my experience i have found Cadence tools are most powerful than any other pcb design software. but takes some time to learn tools.
Pcad is an easy software to learn but it is has not much powerful tools like in allegro. For ex: consraint, length matching, die making, saving components from a single pcb. On the other hand altium is an advance software but still you need to learn altium tool . Designer are using Cadence tool for high speed, match length, differntial and complex routing, blind burried vias pcb. So i would recommend you to use Cadence if you have know how of pcb design software. and if you are just beigner use Pcad.
regard
SA