I've decided to renew the class 1. The price difference isn't significant and a few people have suggested to me that the CAA are potentially more helpful if you hold a class 1.
Fortunately I don't yet have to worry about whether a CPL/ATPL remains valid with class 2 privileges when the class 1 privileges expire, but I do think they could make it all a lot clearer. You shouldn't be expected to have a law degree just to be a pilot!