There’s some of the stuff I don’t agree with, but I’m totally biased (being an Umbraco fan boy and everything) :-P
I’ll comment on this once all the parts are posted.

One thing though: It seems like Sitecore is trying hard to be/include more that one thing: Being a CMS, Marketing Platform and Analytics package. Umbraco will never do this (according to the founder), but only do one thing (good): Being a CMS and a content framework.

So with these two totally different approaches, one will always have more stuff/features than the other. And in my experience, that’s not necessarily a good thing.

But keep up the good work! Looking very much forward to the next parts, hoping they are equally well written