I think mudguards are worth fitting, you have to be more careful reversing up to kerbs though because if mudguard hits kerb and gets pushed onto tyre it can put a strain on mounting screws etc. also in winter (if it snows) the snow tends to pack up between wheels and mudguards (especially front wheel) - but looking at last run of winters snow was not on the agenda anyway.
A lot of broken windscreens may be down to lack of mudguards on other vehicles, allowing stones to kick up higher.