EMD update a penalty? OR does it simply devalue an EMD's weight?

Here is my experience:

About 60 EMD's took a spanking to oblivion for 1 day. 95% of them came back to original rankings the following day. Part of this may have been G flexing it's muscles. It is important, however, to point out that none of my sites are adsense - just splash pages for local businesses.

EMD's definitely don't have the upper hand in a strategy anymore.

It's a penalty, here is where I got my conclusion from:

I needed to dominate 1st page for a keyword, so I got the regular EMDs, and some non-EMDs to fill in the last couple of spots. The work done on all these domains was more or less the same, and the keyword is easy/easy-medium competition. I had every spot from #6 till #15 with my domains.

After the EMD update, my EMDs are out of top100, where the domains registered the same day, with the same work done on them - still #9-15

I have about 6 / 8 EMDs that are full legitamate ecommerce sites making thousands a day but they have been hit. These are product pages and I have sites that were built the same way as far as backlinks. One was on the WP platform with a blog on the actual domain and it looks like that one is doing well while the others got hit.

I am curious if this is just an emd if anyone has just transferred their site into a new domain and 301ed over

I've heard that if there is insufficient content on the site, and if the content is not of very high quality, then an EMD site will be penalized for it.

Sites like Ebay will obviously continue to show up #1 for "ebay".