As I said, previously, I'm afraid I can't be much help here.
There are methods to protect oneself whether you are a home user,
an SMB, or a lerge-ish entity...
If it comes to down to business decisons, then do whatever
business dictates.
But me -- I'm an engineer/instigator. 
- ferg
John,
Contrary to popular belief, I (not alone, of course) run,
manage, defend, and continually architect very large
networks. Very large. On none of them do we outsource
the protection of them -- because, in cases where we
have extended trust in the past, we have been screwed
(PC translation: disappointed).So we protect ourselves.
It's been a business decision for my customers' networks
(ie. their network) not to outsource security, or rely on
an upstreampipedream, for protection of any sort.Thus, I personally can't provide any insight here. Sorry.
- ferg
Ferg,
Not everyone is in a position to have anetwork large enough to be
"self-defending". I think he has clearly stated they are not in a
position from a capacity standpoint to self-defend. If he has a few sites
with some T1's or DS3's or whatever, his goal is to not stop the traffic
at his router, but not ever allow the traffic onto his pipe.
I too have been involved in large, very large, networks and we used to see
it happen everyday. Customers with OC12's getting smoked off the planet
because of some kiddie made someone else mad in IRC. If the upstream
offers a "value add" service such as DoS protection, why balk at it?
-j