Hi. I too get this sometimes - sometimes an instant crash - sometimes it hangs until i kill it off.
This is only with Yosemite and 9.x i never had many problems with Mavericks...
THOUGH since i stopped Notes using its internal web browser - i have not had a crash... not ideal, as i liked having a notes specific web environment - however, not having 20 crashes in a day is really a great result.
I notice that there is no longer much traffic in the Notes for Apple area, i am guessing we are an increasing minority and as such i am worried for the future.