My MK4 has been nothing but trouble. The Q has been okay-ish, but the screen is so dim even at the brightest that I can't get cameras to scan QR codes on the screen. Meanwhile, SeedSigner works just fine. ColdCards are way overrated after actually using them. I'm probably done with them. SeedSigner in general has a more positive team in my experience and I like their ethos better. Not for everyone, but it really taught me a lot I would recommend using hammer in pins instead of soldering if you plan to build one yourself though. The project leader sells assembled kits. @SeedSigner