I made the switch 3 months ago.... and thank goodness.
Using HPOpenView was such a pain in the rear :) I got away from HPOv almost immediately after being tasked to take over our sensor network.
From that point on I wrote custom this and custom that to interface in to the Oracle database I had the director pumping information in to.
Now that I have CSPM, it comes with it's fair share of problems (as noted by my 'howto' questions, and currently open TAC cases), but it's a step in the right direction.
Again you can populate a database, which I like, although that function is not 'built in'; it's a custom process that involves the use of a cspm utility.
But still I've written custom before and will continue to do, I expect that; but I am more pleased with the CSPM package than if I had director thrown in to my lap.
Go ahead and make the switch....
BTW if you were not using an external with director, and have no experience with that, then switching to CSPM should be a definite yes.