Since the original post and discussion is a bit dated, one has to realize that Xara has moved forward with the block solution for those touting Wordpress. Flexible blocks now offer a much more elegant solution than Wordpress.
This discussion could continue for a long time with advantages and disadvantages.

The deal breaker for me is the cost of many add ons. You add it up with everything that today’s mobile crowd wants and it becomes very, very pricey.
My clients may want something that Xara can’t supply and I simply tell them. I’ve received no push back. With Wordpress you have to tell your client that that will be an extra $10 a month and it does not compute.