We had both. Spam comments and then spam external links to good blog enties. Then we had a hack where they posted 40,000 spam blog entries (hidden) and then generated tens of thousands of spam external links to those spam blog entries without us knowing or realizing it. Once we saw them we cleaned it up, deleted and 410'd the spam blog entries, but the damage was done.
@ Planet13 - We never got the "manual penalty" email but were hit by algprithmic penalties (Penguin and Panda) soon after. Are you saying we should submit a reconsideration request even if we didn't get a manual penalty notice?
I think we still have the logs saved. The backlink profile speaks for itself too. We have a craft site with a bunch of women... and then our backlink profile is littered with tens of thousands of backlinks with anchor text of "viagra" "seo software" "#*$! site" etc.
We did the dissavow tool for as many as we could track down.
I will certainly submit a reconsideration request if experts here think it might actually get looked at.