I've had some candys since I picked some up in America when the pound was worth something. Before that I used SPDs. And before that I used those weird strap things who's brand name I forget. They were purple with yellow writing so probably best forgotten.
The SPDs I really liked. But the CR candys just seem to click in & out a bit easier. And they certainly work better in snow & ice than SPDs.
No service issues yet with the candys but I liked the way that the LX-type SPDs could have an easy grease refresh.
I prefer the CRs, but the click-in is nowhere near as certain as the SPDs – no resonant 'click!'. And they do pop out if you step over rocks on your pedalling foot.