I've rolled out ESET Security suite, 8-11 now I think, on several dozen PCs, servers, laptops for the last 20+ yrs. It is highly configurable and hasn't missed a beat.
If you buy 5/10+ for 2-3 yrs block, it's damn cheap. We pay ~$12-15.00ea for 75seat yrs
My vote is for ESET NOD32 AV as well. I have been using it for several years and chose it exactly because it is lean and does not bug me with unnecessary messages.
I don't have experience on an enterprise environment, though.
My suggestion is Eset. Works fine so far at my computers and is not very expensive.
Thank you everyone for their suggestions. I thought I'd respond with my findings in case there is anyone else looking for a similar product.
After trialing a few different packages, I've settled with
ESET NOD32 Antivirus. It does exactly what I need it to do all while sitting in the background quietly.
As a bonus, the latest version also runs on Windows XP (which I have one machine running legacy software) and on Windows Server. Updates are rolled out several times a day and I particularly like their
update information page which lets you see exactly which viruses etc... are being detected by that pattern file version (something a lot of AV providers don't provide, you just have to trust they get the latest stuff).
It uses a relatively small amount of resources and doesn't seem to effect the general speed of things even with real-time file scanning enabled.
Pricing is also very competitive and you can choose exactly the number of licenses you need (rather than forking out for a 5-pack if you only need 3).
I like it
Take a look at their Security Suite versions. I've upgraded all our PCs to SS .. The suite has NOD32 plus several other very useful features, including 1 cool one -
Installed on a laptop - if it ever gets stolen, next time it sees an Internet connection, it secretly phones home :-) buried in the updates