Interesting question.
I also had the same quandry. I'm also in the aging eyes category too. The Nokia has a much better screen and zoom capability but I guess if it comes to a decision on which I would take the stock "sales" question and ask what you are using it for? Being an ex-Zaurus guy as well I'd lean you towards the Nokia. You put uses in your original post but here is a quick use case comparison.
1150
+Cheaper ~$100
+More rugged
-Single purpose device
+Longer battery life
-Display is not the best
So if you beat the crap out of your stuff this is the way to go.
Nokia N800
-More expensive ~$280
-Less Rugged - I'm still apprehensive holding it and I know I'll snap off the web cam eventually
+Multipurpose device - has all sorts of stuff that you are probably aware of
-Less battery life; especially when you are surfing the web, chatting, listening to MP3's, watching videos, etc.
+Text and screen are very sharp and you can zoom to your hearts content
+You can read online when you are connected to wireless
+I put my ebooks on my own webserver and can download/read them whenever I want
+"Reference" - look it up on the Internet with the Nokia
So what do I do? I bought and use both
