Agree about plug change, any vehicle I get I will put new plugs in, as I would not know how old the one's in there would be, then I would not change them again in ownership, unless a fault occurred.
Regarding checking plugs, on the Wee I do not find it a pain, can do front and rear plug in about 1/2 hour, only one bolt at front and swing rad up, and just one bolt at rear to release tank.
You should do the plugs on a BMW F650GS, now that is a pain.