We have done both and would agree with the prevailing advice to choose the Baltic. We were scheduled for Russia/Scandinavia with a group of friends this last July. Obviously, the Russia port did not happen. We were disappointed for all our friends, none of whom have been to Russia (We have been and it’s a fabulous port), but the addition of an overnight in Stockholm and a day in Copenhagen made for a great cruise.
We love the UK but after our first British Isles cruise, we felt we wanted to do a land trip. We spent almost two months in Scotland and England this last summer and it was wonderful.