Firstly, I must draw attention to the fact that my intention is not to spew bile, or communicate zealot-ism of any shape or form.
A definite consideration is that it is often impossible to change anything major as a third party software suite you are developing on top of midway, for all sorts of reasons, the most notable being expense and time/delay to finish.
WPF is such a flexible platform, I would advocate getting the business logic and functionality of an application thrashed out first, then look to a design team or third-party suite right at the end the end or during the process, rather than automatically restricting oneself from the offset with a third party suite.
This, however, is seldom practicable, as the product owner/customer will need to be interacting with the software as time progresses, and they want to see something pretty, there is hardly ever any flexibility here, the application has to look stunning very soon into the start of the project, in order to gain their confidence (and settle their nerves) and continue in this vein.
There is nothing like , a trite but often unavoidable word when reflecting on a projects progression, It is always harder to be objective at a later date, because quite often, a quite different set of circumstances and considerations result due to the fact that time has moved on, and better ways of dealing with technical challenges and vendors present themselves.
the steps required to solve particular problems become perspicacious.