Is big G really that slow?

One of my money sites lost rankings considerably and ranked on the very last page for keywords where it used to be on page 1 or even 1st position. Site was still indexed. To me it's a standard penalty because I did not pay enough attention to IP pop and put some links from my own network. Overall, the site had like 30 referring domains from only 10 IPs or so. I removed the links and waited 3 weeks.

Now, the site ranks for certain keyword clusters on top positions again. So far I can only find 2 clusters and it's only like 8 uniques/day. I'm checking rankings regularly and one week later I see exactly 0 improvements for other clusters. For the exact match it sticks on 6th position where it was a few days after the penalty.

I'm pretty lost here. Does it take over 1 week for Google to update all databases? Do you guys have any similar experiences? I know that 4 weeks is not that long for a penalty to stop but why are some rankings back to normal and others not even close?

It can take months for there to be changes in Google rankings. Keep in mind that in '08 it was estimated that there was almost 200 million websites. Give google a little slack.

Also, you only have 30 backlinks. That's not nearly enough and there's no excuse for having only 30 backlinks. I just hit #1 on my targeted keyword for one of my niche sites and it has 20,000 backlinks.

I don't know why backlinks should matter here. These are all powerful backlinks that do their job and I was referring to unique domains. So overall I have a few thousands not just 30. Why should I build non quality backlinks when the few backlinks do their job? How is that supposed to help overcoming a penalty? Is there any influence? The more backlinks you have the easier you come back from penalties? Please explain.

It's simple math.

More backlinks = Higher Ranking

Obviously the higher PR the backlinks, the better. At the end of the day though, a link is a link. It's worth something in the eyes of Google. If it wasn't why have hundreds of thousands of dollars been spent on buying or developing software like Xrumer, Scrapebox, Scrapeboard, and all the shitty knock-off's imbetween.

I really don't believe in any kind of link building penalties or anything like that. Otherwise it would be abused left and right

I appreciate your advice but backlinks are not the problem in this case. My question is why the penalty does not affect certain keyword combinations but is still valid for 95 % of keywords combinations? And this for about 10 days already.