Firstly I think that Xara is the best most usable vector program at any price but for my work editing weddings it is just a non starter.
The average wedding that I will work on consists of over 300 raw files every image for my clients gets individual treatment, some re-touching gives me a bad head and thats with a full range of tools that I know how to use. Another big plus with Photoshop is scripting and actions that save me days of work not just a few seconds.
My advice is to use the best program for the job, and in many cases that would be Xara but when needed Photoshop has no equals.
Watch a few of these short films by someone that does know how to use Photoshop and you will see just how powerful it is.
http://www.russellbrown.com/tips_tech.html