I live in Boston. It is a great city - very easy, beautiful, lots of history. Fab symphony, Tanglewood during the summer, good culture, lots o broadway shows come, Nutcracker every christmas.
You probably won't want to live in Boston itself but in one of the nearby towns or cities. A lot will depend on where your husband is working.
The biggest issue in deciding where to live will be school districts. Once you rent or buy a house in a district, your children are entitled to be enrolled in the schools - no big hassle about wait lists or anything, the only lottery is in Boston itself. They will go to the local school with all the neighbourhood kids. So you will want to pick by school district. Brookline is brilliant as are towns like Arlington, Winchester, Weston, Wellesley, Andover, North Andover, Lexington, Concord (god Concord is lovely - you would feel like you are living in a currer and ives print).
A lot of town/city spirit is based in the schools too so once your children are in school, it will be easier for you to connect to the community and make friends.
If you want your children to continue in the UK system there is a British International School. Fees will be high.
In the US system, your chiildren would be going in to grades 3 and 6 I think.
Make sure he gets excellent health care as part of his package of benefits.
Ask your husband to check out where his colleagues in Boston live.