[c-nsp] How many routers per OSPF area?

[Hank Nussbacher]

Alcatel says 200:
http://archives.neohapsis.com/archives/microsoft/various/ospf/2001-q1/0202.html
"Concerning the number of router per area, we generally consider that the 
maximum number of router per AS is 200."

IS-IS Wiki says 50:
http://en.wikipedia.org/wiki/IS-IS
"While OSPF only supports 50 routers in a single area, IS-IS can support up 
to one thousand routers per area."
[and no, the OSPF Wikipedia entry doesn't state anything on the matter]

Imagestream says 40-50:
http://support.imagestream.com/OSPF.html
"Nevertheless, a general rule of thumb is to limit areas to no more than 40 
or 50 routers to ensure adequate OSPF network performance."

Cisco is non-commital:
http://www.cisco.com/warp/public/104/1.html#t40
"The maximum number of routers per area depends on several factors, 
including the following:
What kind of area do you have?
What kind of CPU power do you have in that area?
What kind of media?
Will you be running OSPF in NBMA mode?
Is your NBMA network meshed?
Do you have a lot of external LSAs in the network?
Are other areas well summarized?
For this reason, it's difficult to specify a maximum number of routers per 
area. Consult your local sales or system engineer for specific network 
design help."

Data Network Resource says 60-80:
http://www.rhyshaden.com/ospf.htm
"60-80 routers are considered to be the maximum to have in one area."

So, what to do you use and if you follow some other rule of thumb, do you 
have a web reference to point me to?

Thanks,
Hank Nussbacher
http://www.interall.co.il