If an inbuilt battery goes duff the whole machine is waste

A good point but there is such a thing as a memory bank and recorders will record whilst charging.

Organising the charging of equipment is about as forget-making as carrying spare batteries which get used for many things and not replaced. Golden rule is have a check list before you set out.

I am not that organised (some of the time), which is why I have the smart watch. The other wrist recorders served well until they didn't.
And I have an Android phone which has the sound recorder - and it has got me out of a hole several times. I set my H2N going alongside the Android and leave the Android running longer incase people say "I just remembered........"

the OP is asking about convenience, So I would say go for a memo/note taker - size of a pack of cigarettes or less. Or a smart watch. H2N for quality and shotgun mic mode for cutting extraneous noise, but it is a bit big for quickly catching the moment, even if it can pre-record 10 seconds before you hit record.