I went on this trip a couple of years ago, and I'm sure you'll enjoy it.
My only concern is the cost, Russia is very expensive in terms of hotels, which is a major part of the holiday cost, also you'll find food and drinks pricy, although in overall terms I doubt that this will add up to much extra expenditure because it's only a short break.
Additionally a visa costs around £150, which (in terms of cost/day), makes it probably the most expensive European holidays offered by JY.
Stuart