About the comment here I think Plone doesn't work like that (at least not anymore).
1 - Plone is somehow slower than other CMS solutions indeed, but from the out-of-the-box setup to a Apache-Varnish-Zope-Relstorage solution, there is a lot of optimization space.
2 - That is true. The answer here kind of explains it, but indeed Plone is a complex animal.
3 - Not sure what you mean. TAL Path expressions are based on the concept of object attribute traversal. Seems OO to me.
4 - True. Although after you understand how Acquisition works, it stays out of your way. And in Plone not many things depend on Acquisition, I guess.
5 - Not true. Zope Page Templates are all about separating content from presentation. The fact that content and presentation can be viewed from the ZODB (and actually most of the templates stay in the filesystem, you just see a "view" of them in the ZODB) is more related to the fact that the ZODB is a big object database - which in turn does not mean that they are all content. Everything in "pure" OO system is an object, it is just the kind of object (presentation objects, content object, etc) that matters.
6 - Plone does distinguish between webdesigners and content creators. The designers do all customizations (templates, CSSs, JSs,etc) and then content creators create the content using Plone UI. The point here is that Plone is mainly a CMS, which means that content creators are supposed to be laymen in terms of design.
7 - Partially true. Considering that the UI structure won't change, all presentation specification is contained in CSS files. If the UI structure needs to change, the designer might work with a plogrammer :-) to adequate the templates.
I guess in no system that outputs dynamic pages the designer is completely free to speak only HTML, CSS and JS, and leave out some other technology, be it PHP, Python, ASP or Java. If he does, there will be definitely a programmer that will get the HTML,CSS and JS from the designer and "dynamize it". This model definitely exists in Plone.