Another problem with SFF: proprietary case and/or power supply designs. I got bitten by that one with an old Shuttle cube. Great-looking design, but it was not

Another problem with SFF: proprietary case and/or power supply designs. I got bitten by that one with an old Shuttle cube. Great-looking design, but it was not mITX, it was its own thing. When it became too obsolete, there was no upgrade path.