Hi multiprose!
Which is right for you depends on where and for what you'll use it. There are several minor differences (stylus in different location, removable battery on EE, 2 USB ports on EE, etc.), and the smaller PE adapts better to the Ermine upgrade.
There are threads in this forum comparing the two, although you might have trouble finding them.

I have both, and I use them both daily. I use my EE more (on it now), but if I could only have one -- I was going to say it would be the PE (more versatile), but if I get a Galaxy Note that would partly replace the PE and I would still want my EE as my primary ereader and light gaming device.
Good luck deciding!!