What is the ideal smartphone screen size?

I've used many different types of smartphones over the years and I have often wondered, "what is the ideal screen size for a smartphone?" At first, 3.5" seemed like a standard size. Then, we saw a flurry of Android smartphones with screens larger than 4" and I got used to the new size. Now, I find myself drawn to try devices like the Samsung Galaxy Note II that has a screen size of 5.55" and this is a "phablet" device which is a cross between a phone and a tablet. If a phablet is the right compromise, then maybe that's the right type of device that I need.

I'm also still a pen-based user (because I like to scribble notes), so larger devices that support an active stylus pen are attractive to me. Verizon currently offers the LG Intuition that has a 5" screen, but this device seems a bit too blocky to me. The Samsung Galaxy Note II is coming to almost every major wireless provider, so I plan to test one when it comes to Verizon. While I wait, I'll continue to use my iPhone 5 (which is a great phone, but the screen is still a bit too small for my taste).