You can't really say they are doorsteps...The PIX firewalls do more than a good job at what they are built to do.
The 535 is not End of Sale yet, now my 2-520's were EOL in 2001 and I'm still using them fine. They are workhorses and I haven't had to reboot them in years. A PIX is basically a PII motheboard/CPU with a proprietary Cisco flash card.