Overall I'm pretty satisfied. The EVO is far from perfect, but no phone is.
The main thing I'm disappointed in is HTC Sense. It adds some great features to stock Android, but it has it's share of bugs and issues that are not present in stock Android. Overall, I'd say it's a wash between pros and cons. Given that this is the 2nd generation of Sense for Android, I expected better.
Other than that, I'm finding the EVO to be very good.
Battery life is better than I expected (after reading the horrible reviews) I've had no issues with WiFi. I live in the Philly area, but just outside the 4G coverage area. When I go into the city, I've found that the 4G speeds are very good, so I'm excited to see that network grow (though I have a feeling that when LTE is established it will be the 4G network of choice) Also, it may seem trivial, but I love the bigger screen. I think anything larger would be too cumbersome to carry, but my iPhone screen looks absolutely tiny now !
As far as Sprint (since this is my first Sprint phone) I've found that there are a few more dead spots in my area than with ATT, but the EVO does an amazing job of hanging onto a call even with a weak signal (though I believe part of the credit goes to CDMA vs GSM as I though I read that CDMA does a better job with weak signals) The only calls I have dropped with the EVO have been because I went through a dead zone. With the iPhone, I dropped calls at my home with full bars (and without even moving the phone)
I don't think there is a phone out there that performs as well as it's specs indicate it should, but the EVO is as good as any phone on the market now. There are other phones out there just as good, but none with the larger 4.3" screen.
There is enough feedback from users and the "professional" bloggers that it's very easy to make an informed decision as to if EVO is right for you.