Just got my pair, and the foam ear tips are totally not working for me. Getting a good seal is a physics problem with about a .2 chance of success, and it's unstable to boot. Also, they're very itchy, making frequent adjustments necessary, which compounds the fitting challenge. Any size under the largest falls out, and the large size exerts pressure, making them quite uncomfortable to wear. In contrast, I often forget I'm wearing my Bose QC II, which was also the case for the AirPods Pro 2, while I had them. I think it helps a lot that the latter two have oval-shaped tips.
I have some silicone tips from an old pair of Panasonic buds that are a perfect fit for the XM5, both for the buds and my ears, but they lack the protective inner mesh of the Sony tips, so I'm not comfortable using them. Does Sony make alternative tips for these? Have they ever made tips with different materials, or at least additional sizes?
Besides helping greatly with the fit and comfort, the silicone tips also greatly reduce the low frequency thuds I hear from my footsteps and when I move my jaw. If I can't find suitable replacement tips with the mesh, these earbuds are going back for sure.