Thanks for the welcome and the advice everyone. Much appreciated.

Thus far, my 5 flights to DC have been on BA, not through any particular sense of loyalty, but because they have offered the cheapest flight at the times I was looking to travel.
I've built up a fair few Avios already (though have little idea what to do with them yet - that'll be my next task). I hadn't appreciated the Avios boost that came with Silver though - as stated, that would make it effectively self financing.

Unfortunately we won't be able to have a few days away when I'm over there - all time when bloke is off work is already accounted for in visiting his Grandma in Ohio for her 100th birthday, but thanks to the suggestions here, it looks like a day trip to Boston is on the cards, coupled with a nice lunch with an old friend who lives there.

I guess I'm really looking to achieve a balance between comfort and cost, and just trying to make the whole business of getting there a little less stressful.

Since this is such a friendly place, I think I'll stick around - more than likely loitering in the background as I'll have little to contribute, but lots to learn