There is now a comparision at Edutools between webct6 and moodle 1.5. Maybe it has been there a while but I have only just seen it.

The decsion tools looks interesting. You identify a series of criteria, weight them, score the 2 products on a scale and it will give you a “decision”. You need to be pretty familiar with the products to do it properly but as it will allow you at add your own criteria, we may be able to adapt itas part of our evaluation.