So far, I really like this mouthpiece, here's the cliff notes version of my review:
Mouthpiece feels good, and works well for my needs.
Mouthpiece looks good, even on the vintage horn I'm using it with.
Communication with ACB was great, but strongly I recommend contacting them before buying anything.
My only con is it felt like it took forever to arrive, but it's a custom machined product, and I ordered it during a pandemic.
The long version: I had to get a new mouthpiece... I was using a one hundred year old "V" cup of unknown make and size, for the last decade and a half. It had it's problems, but I liked the sound it made, and the fact that it was "so vintage" had a definite cool factor, so I kept using it. I then, by chance, discovered the vintage nickel-silver alloy it was made with, contained lead, so I had to stop using it, despite how much I loved it. I got it plated, but the plating started to flake off after about a year, so I decided it was time for a new one, and I didn't want to risk another vintage piece.
I knew ACB could do custom pieces so I reached out to them, to find something that would perform similar to my piece, but would be safe to use. I spoke with Josh over email, and he recommended the 1.25 CS-b, and that's what I decided to go with. He told me that the TF cup would have been more similar to what I already had, but I told him since I was getting something new, "a little more projection" and "easier to play for long concerts" would be nice, and so he recommended the b cup instead. I caution you, definitely don't just order something random without talking to them, there are too many options and you might not get what you need, and their system of sizing and rims is not very intuitive.
I should note, it did take several weeks longer to arrive than advertised, but as I said, it's a pandemic right now, so I think that's forgivable. I did check in at the 12 (I think) week mark for an update, and one was given to me that same day, they were waiting on their plating shop. I'm sure this could happen again, so if you need something fast, (and definitely, test your vintage pieces for lead, guys) don't go the custom route. I was starting to feel a bit impatient, but in the end, it was worth the wait for me.
After the piece arrived I started to play with it at home. I haven't had a chance to take it to brass practice, yet, and might update this review if I have any issues, but after several hours of playing I think it'll be fine. With that said, it slots differently than my vintage piece. A lot... I checked myself with a tuner, and everything is good though, so either my old piece was wrong for years (oops), or I've already gotten used to the new one. I will say, it did start to feel much more "normal sounding" after I found my ideal embouchure for this piece, which took about an hour of playing, and isn't quite where I expected it to be. I feel like it's pretty reasonable for two mouthpieces designed over a hundred (estimate) years apart to feel and sound different though.
I haven't played long enough in one go to comment on endurance, or at least I don't think so. It feels like I can go forever, but a grueling practice with my brass group will be the real test, as opposed to just messing around in my living room doing scales and playing memorized bits of the Hummel concerto a hundred times. The tone is lovely! It's brighter for sure than my vintage piece, but still feels very "cornet", and not at all "trumpet". I honestly prefer this tone to my vintage piece, which surprised me greatly. It's not near as bright as my Bach 3C piece, which I stopped using ages ago, because it was too bright. It has really, REALLY helped with my perceived projection. I can blow exceptionally loud with little fatigue, compared to both my vintage piece, or my 3C, which is important; my vintage cornet has a really hard time with solos over a large band. At first I felt like my range was suffering, but after finding my new "correct" embouchure for this piece, I can play just as high as before, which for me on a normal day, is the F above the staff, (I never could hit above that on cornet on any mouthpiece, with any semblance of consistency, but I also never need to for what I play in my particular brass group.)
Lastly it looks good. I'm not a big fan of brushed finishes, but after seeing it in person, it looks about fifty times better than the photos on the website, IMO. It looks heavy in the photos, but not so in person. It feels very light, and I'd say is only slightly heavier than my vintage piece. The smooth lines and lack of knurling/ornamentation gives it a strong "YORK-ALTRU mouthpiece from the early 20's" vibe, that looks great on my vintage York Perfectone cornet, but would look just as great on a modern horn. The rim, despite being labeled as a 1.25, is more narrow than my vintage piece, but I'm adjusting to it quickly. Josh said that would be the case. Having not played a lot of orchestral trumpet mouthpieces, the 1.25CS rim feels maybe a smidge larger than my 3C, but not as big as a 1.5C (trumpet), but it's really hard to tell by feel, and I'm not going to bother with calipers because frankly I don't care... Like I said, I had adjusted to it after like 2 hours of playing or so, and it's thus far continually getting easier.
My final note is since I got this piece, I'm practicing a lot more than I did, and having fun doing it... Apparently my old rig, though I loved it, was getting stale, and it was definitely time for a change. Time will tell if the piece is really that great, or if it's placebo because I apparently needed something new in my life to make it fresh and exciting. I do plan on trying some additional new stuff in the future here though, but I'm very happy with my purchase, and recommend reaching out to these guys, if playing is starting to feel stale for you also, or if you want to diversify your mouthpiece collection for the specific genres you play. I'll probably get a TF cup for my next purchase, but who knows...