Thanks BP. I certainly intend to get my radio licence at a similar time to going cross country, but in ~80 flights the radio in any glider I fly (if one is even fitted) has never been switched on. Very different to PPL as you say.
Out of interest I checked my "Bronze and Beyond" book (a well-endorsed book for glider pilots in the transition from first solo to early cross country flying) - there is a section on landing out at airfields- it mentions that landing on a runway is preferable to landing alongside one, due to the unknown state of the surroundings to the runway (potholes etc).
It does mention the importance of radioing your intentions and checking for other traffic in the circuit though, and of pulling your glider off the runway as soon as possible.