I used protel 1.0 , protel 1.5 , protel 99 , protel DXP and PCAD.
I think Protel DXP is a very powerful tool for PCB and circuit design . it has a compatible spice engine for circuit simlation.
I didnt like PCAD because it lacks libraries , you have to define the foot print for each component you use , and this will consume alot of your development time.
I have a friend who worked as a pcb designer , he told me that mentor PADS/Expenditure are more powerful and professional than Protel . I havent tried it but I think he was very honest in his judgement.
I have seen a discussion on this site in which a comparison was held between Cadstar and Protel. In this discussion someone said, "dont compare a man and a kid, protel is a kid !!!". For myself, I have never tried Cadstar , but you should consider it in your selection process , since you havent learnt any of these tools yet
what do you think ?
P.S. I dont know why " P R O T E L " is written like protel on this site !