Nicely done! I didn't notice too much of a difference when I installed my M3 transmission mounts, but thought it couldn't hurt.
As far as exhaust sound, it's such a subjective thing. However, I completely agree the ZHP exhaust is a definite improvement over the 330i stock exhaust! If I had a 330i, I'd jump on that in an instant. I picked up my UUC TSE3 exhaust because I had a chance to get it for very cheap. It's hard to justify $900+ for something that has no improvement in noticeable performance. Yes, you experience the sound every day, but still tough IMO when mechanical maintenance should come as a priority. I'd say a nice "cheap" bump from the ZHP exhaust is the BMW Performance or the Dinan axle backs if you can find them for a decent price. My sister's ZHP has the Dinan and I really like it, just enough of a growly bump. The TSE3 is childish with its increased volume, growl, pops and burbles, but it puts a smile on my face.