Specifically, on Home Menu/storage R/W operations. It's most noticeable on systems that were already a bit slower than stock- anything running on a 128GB microSD card that the 3DS doesn't play along with well, for example. It's not a SD card speed class issue- no 128GB cards exist below Class-10. Preexisting issues with some 128GB cards are well-known- one example is visual corruption in GBA VC titles on problematic cards, irrespective of cluster size. I've noticed that there's more hanging/stuttering when navigating the Home Menu's grid with the D-Pad held down to the point where the cursor is moving automatically (stuttering as it attempts to load banners) and significantly longer hanging when taking a screenshot with the Home Menu's own built-in functionality. Additionally- when attempting to take a screenshot in that way, I occasionally get an error dialog stating "A microSD Card process failed"- I've never seen that occur on older versions of Luma, and it seems to happen too erratically for me to be able to pin down a direct chain of events leading up to it. I don't necessarily want to go filing an issue report without any further corroboration- the difference is noticeable to me (and entirely unexpected), but some extra evidence that it's not just psychological (beyond the error messages) would be nice. Replies from users running on 128GB microSD cards that were already having minor issues on older CFW versions would be particularly appreciated. Edit: Got it. One way of (semi-regularly) reproducing the SD card read issue is to attempt to take a screenshot when the system is just resuming from sleep mode- can this be reproduced on stock/older CFW versions?