I think that any cerfification is worth something if we study them the right way.
For example, I currently admin a six office VPN based completely on Sonicwall firewall/nat routers. I learned enough about VNP's and NAT routing from the CCNA exam that I, even if I don't admin Cisco equipment, I was still familiar enough with the concept to run things at my current job.
A firewall's access list will always do one of two things - accept or reject packets. The platform (I.E Cisco, Nortel, Microsoft) you put the ACL on won't make a difference.
Learn the concept, not the exam..... does that make sence?