Cirque du Soleil's annual post-Christmas London residency at the Royal Albert Hall has become as synonymous with this grand concert venue as the summertime BBC Proms; and while some of the nine big top and arena shows they've brought here over the years since they first appeared here in 1996 have felt excessively padded and occasionally even generic, Totem could be said to be totemic of this brand at its fantastic best.That's when a true theatricality informs the usual parade of astounding feats...