Ive been using Zoom notes for over 3 years now and Ive tried just about every full featured note app in the store. Zoom-notes is by far the better app in this category. Unlike many of the note apps, you can have a different style page or paper for every page in your note books. For me, this was essential for taking notes in a lab environment where data comes in all shapes and styles. Making data gathering templates and saving them as "Paper" is a huge time saver and ensures your note always have a consistent look.
Importing PDF, google docs and photos into one neat and organized note book is where the power of this app shines. Import multiple photos at one time, no more hitting import, select photo, paste and repeat. You can even import photos from the camera right on your current page within the app.
Being able to edit pen styles, text styles and line and shape styles is a real time saver, especially since you can save these options in groups for later recall.
Did you delete something by accident? No problem, files are deleted into a recycle bin first. While hand writing a note, if you make a mistake, just scribble it out and it goes away, no need to hit undo or select and delete, but you can if thats what youre comfortable with.
Update: Since the Apple Pencil came out, writing notes is now a real blessing. You can place your entire wrist on the screen and there are no errant marks to be found. No real need to use the Zoom writing tool, just zoom the page up a bit and start writing.
Update 12-02-16
The new documents tab has just doubled my productivity by letting me keep the most relevant documents open all at the same time and they can all be from different folders. This is one of the best features yet, high 5 to who ever suggested this feature be added. ZN is still by far the most versatile notes app available and the only one I use on a daily basis for work and home.