I have a bppc card also and while it's nice to have the ability to run the WarpOS versions of software, there isn't enough to justify the cost.
I own os 4.1Classic, but prefer to run 3.9 instead.
OS4.1 itself runs nice and fast, but all the software written for it generally assumes 4.1 users have more powerful hardware (sam's, peg's, etc..), and is slow on classics. Not to mention with 4.1 you lose access to some valuable software (WHDLoad).
My suggestion is to stick with the 030. And, if you want to run 4.1, get a Sam...