Deckofficer, if both boats were loaded substantially with crew/equipment/provisions for cruising (say 3500 - 4000 lbs.), I suspect that the Cal 40 would perform better in most conditions: the PDQ is obviously going to be much more sensitive to that kind of weight.
Even if you were able to keep weight to a minimum, I also suspect that the Cal 40 would be a better performer to windward.
If you are doing primarily tradewind passages, the PDQ would likely outdo the Cal 40 with the proper cruising sail inventory. Keep in mind that a symmetrical spinnaker is a great cruising sail on a cat due to the absence of a pole. I also find that it is much easier to sail on a broad reach on a cat when conditions pick up because of the reduced risk of broaching.
In any event, there is no easy answer to the question.
Thanks Brad. I'm currently reading Zero to Cruising's blog with their PDQ 32. They are blog masters, I'm into my 3rd day of reading and am only up to 4-28-2011. My old Cal 40 is my only reference boat for cruising and that was limited to Long Beach to Mulege, Baha.
The PDQ 32 is, of course, a different boat but as I recall, it served them very well. Regardless, Mike and Rebecca would be a good source of information on what worked for them - and what didn't, on a small cat with limited load-carrying capability.