Yes - I have the wallet and a BlackBerry. Sometimes it's just quicker to scribble a note than to 1) type my password into the BB, 2) find the notes application and 3) write something with predictive text. When you're in the middle of a conversation it's much less intrusive and (I find) requires less thought (and hence less distraction from the conversation).
Plus, of course, I don't always have my phone with me (heresy these days, I'm sure).
The wallet isn't necessarily superior, but it is in some circumstances. And it might be redundant, at times. The point is that I can be pretty sure I have 'ubiquitous capture'.
I am in the same boat. The note take wallet is best for capturing ideas and such on the fly. To me the role of the BB is being able to look at those ideas/actions - once they have been processed into your system. Paper is fast.