I didn't pick up the M5 (2023) Beryllium Coated, 14.2mm, 32-Ω driver, I might do that later. I got the M5 Pro Golden 150Ω set. The only way to get the Golden 150Ω driver is with the M5 Pro Golden set. There's a difference between the M5 and M5 Pro body tuning. M5 has the ST10S maze acoustic structure and the M5 Pro has ST20P conch-shaped maze acoustic structure, so it's gonna be an apples to oranges comparison of driver sound impressions for people that bought the M5 Pro vs the M5 body. Smabat really wants to give people choices to find a match up that will fit their sound signature, just open your wallets to shell out... hehe.
The M series bodies also use a tuning filter like M4 series, but I can't find any mention of filter / driver recommendations for either M5 or M5 Pro bodies. So far I've tried ST10S 150Ω Yellow, SO 100Ω Black, ST20 40Ω Red and ST20Pro 100Ω Blue with default factory tuned M5 Pro body, they all sounded different (as expected), but pretty good. The improvement using the M5 Pro body vs the M4 body was like night and day. I have not tried the BA on the M5 Pro, but that BA IEM driver sounded good on the M4 body, so might also sound good on the M5 / Pro bodies. I also have the drivers that came with the S1 Bluetooth earbuds which I have not tried on the M5 pro body.
Speaking about the S1, Smabat has a new crowdfunding campaign for a new S2 Bluetooth earbud, but it's only listed on their Chinese language web store (smabat.com). Their English language web store (smabat.cn) does not offer it. From google translation, the S2 is supposed have a lengthened acoustic chamber to increase the bass and the body is supposed to be lighter than the S1. I know people have concerns about the S1 falling out of their ears due to the body design, but they are very stable. My favorite driver on the S1 is (once again) the SO 100Ω Black. I guess I just like the way that driver sounds.