Do you mean Striding Edge mate? It is tricky under winter condition, though you can avoid most of the difficulties if needed. Definitely a crampons and axe route, and many do get caught out if ill prepared. It is a nice day if you ascend Striding and descend Swirral, though the exit/entry to the ridges can be difficult if a cornice builds. In winter, the ascent from Swirls is probably easiest, if not a bit steep. Winter kit, including hardware, always advised,