I've used an E70 for 3 months now
I've had all three of Nokia's gull-winged phones, and still use a 6822 as a backup phone.
Download Opera Mini for surfing most websites, and use the Web browser for gmail, which it handles perfectly. Gmail + the E70 are a neat mobile email solution that I now use for 50-70% of my email (leaving the longer emails for when I get back to my desk).
I've found wifi to work very well, after some initial pain getting the security settings to work. It did take me several hours to get the wifi working on my secured access point but once it worked, it was flawless. And surfing open wifi points is a cinch.
The OS is too slow and complex for my tastes. It takes 5-7 seconds just to open a new memo. That's unacceptable. The keyboard action is too stiff, more work than the 6822. I like to type a lot of memos but it's not practical this phone, despite the generous screen. Why can't I reduce the size of the screen fonts, for instance?
The format of the phone is excellent; it's a bit heavy but provides me so much in that package that I don't mind. Good camera, good video recording, USB connectivity, expandable memory... all nice features. I tried connecting a Bluetooth keyboard (a laser keyboard) but no joy, even after downloading a BT keyboard driver from Nokia.
The software is... second class. Pretty, but flawed in many ways. Switching applications does not work well. Applications run out of memory. I've crashed the phone by exiting a Java application at the wrong moment. The way photos and documents are managed is totally uninuitive. Basic functions like editing a memo take too long. There's no way to display the phone numbers for contacts in the summary, an essential feature. The email manager (which lets one download emails) has no way of deleting emails. And so on. The phone has options like VoIP that are so complex I've not managed to configure them. This is a very bad sign. Why does the phone contain functionality that people cannot use, but cut-back on basic functionality everyone needs? Not a good sign.
I can see many possibilities for such a format, if the software were more intelligent. For example, how about an email system that detects open wifi networks without any prompting and silently downloads and uploads emails as it can, then alerts you when new email arrives.
There are two ways this format can go, IMO. One is to return to a simpler and more sane OS, something like PalmOS. Two is to move to Linux and open source the applications so that the developers of the world can fill in the gaps left by Nokia's QC department. To continue with more buggy and complex software will drive away users. I might buy one more gullwing after this, but if Nokia can't deliver my core requirements, I will probably return to separate devices: AlphaSmart Dana for taking notes, a Palm for my agenda and wireless surfing, and a small, simple, fast phone for voice.