My experience, ymmv, the most work went into configuring everything you need or want the first time. The right drivers for your graphics card, for your webcam, wifi, acpi multimedia keys, etc. Though I don’t use a gnome/kde/DE, so some of that may automagically work for you. After that though, updates don’t tend to break the things you’ve already fixed.
One time in 5 years the names of some acpi keys changed, and I had to update the script, and that wasn’t really arch’s fault. Also Google did a funny thing with their monospaced font that xft couldn’t handle, again not an arch specific thing.
And here’s a hot take for you, I only update about every 18 months. That’s usually how long it takes Discord to become binarily incompatible with installed libraries. Update the keyring first and never a problem.
Wikipedia says the virtual memory cards are compatible between them. But I’ve never done anything with the Memcard Pro. I have messed around with PS2 memory cards and PCSX2 and generally the raw bytes are compatible between the two. I would imagine the M.Pro is the same.