atlrus - 11:12 pm on Nov 7, 2011 (gmt 0) [edited by: atlrus at 11:43 pm (utc) on Nov 7, 2011]
Relevance has always been the key to backlinks and it has not changed. You can easily beat your spammy competitor by getting a very small quantity of highly relevant backlinks.
I was just doing some testing recently. For a website that has been ranked #8 for not very competitive phrase (~20 million results) I got 10 backlinks from websites similar to mine, I think 5 of them had that keyword as an anchor. Two weeks later and I am up to #2 without anything else being done with the website.
I do this type of testing at least once a year to make sure quality still beats quantity and so far have not been disappointed.
I also expect to see result within 2 weeks from recently acquired links and usually do. But again - quality links.
P.S. Getting a high quantity low-quality backlinks also works, but much slower. I have a few competitors that buy butt load of links and they get results, but after doing some investigation it appears that they had acquired most of their links 1-2 years ago (relative to the time their websites show up in decent spots). So prepare for a long wait :)
[edited by: atlrus at 11:43 pm (utc) on Nov 7, 2011]