If you like which-key's UI (and I don't mind it, aside from the timer
thing -- seems like it can be more useful than the current
'describe-bindings' in many cases), then we could ask the author for
this different mode of operation, where the timer only tells the user
how to get this transient menu with hints (pressing C-h), but the menu
itself isn't shown.
Or more generally we'll have such a timer globally, and the message
("use C-h") would be independent from which-key. But which-key can plug
into the "C-h" binding one way or another, to replace describe-bindings
if the user configured it this way.
I'm the author of which-key, and I've been following along but don't
have a strong opinion on whether it should be on by default, so I'll
let you all decide.
I should mention in response to the comments above that this feature
is partially implemented through the following setup (from the
README). It simply sets a long delay for the timer and allows you to
use C-h to trigger the popup.
;; Allow C-h to trigger which-key before it is done automatically
(setq which-key-show-early-on-C-h t)
;; make sure which-key doesn't show normally but refreshes
quickly after it is
;; triggered.
(setq which-key-idle-delay 10000)
(setq which-key-idle-secondary-delay 0.05)
(which-key-mode)