I did the upgrade and while it is cleaner than the plastic one, there is still a minor mess due to the gap at the front. Grinds can also get stuck along the inside of the dosing 'funnel' because of static but RDT and tapping can help. You'll still need to take the holder out to get a good clean done. I've found that the holder is sized for 58mm portafilters as there is a notch in the funnel that can be used to hold your portafilter in place. Using the notch, the chute doses in the middle of the basket. With my 53mm portafilter though, the chute is too far forward so I can't take advantage of it.
Is it worth the cost? Hard to say as it doesn't eliminate the mess but it is a lot better than the plastic one. I still use it but maybe I could have saved some money by getting a dosing funnel instead.