I don't have too strong of a preference one way or the other. However, I have started to switch all of my plugins over to the jQuery ajax rather than post/get because of the flexibility.  

The ajax hooks give the flexibility to install handlers to pre-process, post process, and override just about all of the parameters.    

The only near term issue I see where these features will be very useful will be if we wanted to allow WPEC to behave well in a situation where the AJAX url is not in the same place as the source url.  This will happen if you wanted to cache an entire site, but have the updates flow through using a different domain.    So www.foo.com would serve the content, but ajax post requests could go through to ajax.foo.com.  The asymmetric update is a really easy way for a plugin to allow full site caching but still allow updates.  It is my understanding the the jquery ajax filters can be setup by a script different than the script doing the ajax, and would apply domain wide.

But if you want, I can make the change and retest without any problem.