There are very few NDB’s left within 40 miles of Boston. North of Manchester, NH, most of those are there and are used in approaches, but, south of there, there are very few. I’m sad they are gone. I enjoy using radio navigation. When I learned to fly (mid-nineties), GPS was very much in its infancy, so I radio navigation was all I learned. And I really enjoyed the challenge of it (and feared hand flying holding patterns blind). Then I left flying in 2001, learning how to use GPS since I got back into flying two months ago has been… interesting 
I worry about the day our satellites are taken out by a large disturbance from our sun. Hopefully most airliners have some sort of backup system (although, it’s not like they’ll all come crashing to the ground…). Then again, it’s likely the VOR’s and NDB’s would be taken out by that, too…