Purely from what I've heard and a teeny tiny bit of personal experience with a friend's Honda these already-legendary generators seemed near perfect before. Upping the game didn't seem possible (at the size, cost and dependability) but yet here we are!
Saw these two accessories for Honda generators:
Oil Fill/Checking
https://www.ebay.com/itm/HONDA-GENER...UAAOSwT0talvYB
Extended Run Fuel Tank:
https://www.ebay.com/itm/HONDA-EU220...gAAOSw~y9ZAlOu
Might be old news for some, nice additions IMHO.