Having been through it, it was as seamless as one can imagine. Remember that 99%+ of Mac users have no idea what this means from a technical POV, or understand the amount of magic that allows most Intel software to "just work" on Apple Silicon devices.
The only noticeable seam before the ARM transition was the terribly long and dreadful time between the PowerPC and the ARM when they were using hot ugly inefficient power hungry SpeedStep hobbled x86 and x64 processors jam packed into way too thin a case and hot glued next to swelling batteries without proper ventilation or cooling.