Hi,
I have been using the E61 for sometime now and use it extensively for browsing, checking official mails and working on my demat account. Have not loaded it with too many software but have a huge bundle of applications that run on S60 phones.
Typing is very comfortable and wifi is an added bonus especially since it is much faster than gprs.
However the cons are that ppl might not consider it very showcase worthy since it doesn't have a touchscreen.
I also use it for carrying around presentations sometimes and its fun to be able to walk into a conference room with just the mobile phone and then make the presentation.
A huge minus though is that it is not portable. You cannot just slip it into your pocket. It makes an ugle bulge and I had to hunt around a lot for a case till my spouse stumbled upon a Capdase case while shopping.