I have a note with around 20 images - all photos taken (from within Agenda) at a conference of slides and flipcharts. (Using Agenda on iPhone)
After a few images I found the behaviour of the Note to be weird. This included being slow to scroll within the note, lots of white space where there should have been text or images, diffcult to place the cursor where I wanted to type.
It seemed especially bad when I woke up my iPhone - sometimes I had to navigate to another note and then make to make it behave.
Also, turning the phone landscape to take a photo made the screen elements become misaligned.