I've had mine since September, so 8 months now with no issues at all. I got my girlfriend the Desire for her birthday, and we just switched for the week because she always liked having a keyboard, going to see if she likes it enough to keep it.
Not sure exactly what you mean by not being a smartphone, what is it that it can't do that your other phone can? I like the look of the desire better, and the bigger screen and slightly less lag, but I can't say that it's $150 worth better which is the price difference. I had to pay almost full price for the Shine plus but only the 3yr price for the Desire, so it was a no brainer.
I feel like I have to be much more delicate with the Desire, cause it feels fragile compared to the Shine. I have more confidence in the Shine holding up to my girlfriends usage.