Prospective purchase

I’m getting fed up with my current phone’s increasing tendency to turn itself off when it feels like it’s working too hard (for example, when it receives a call or sends a text). I don’t use a mobile phone that much so I don’t want anything too expensive, but I’d like the ability to sync with my calendar and nag me. I’m thinking of buying one of these. Does anyone have experience with anything similar? Is this a good idea or not?