There's a VGS at Henlow.
As for the original question. Houses haven't been upgraded recently apart from a few that have had new boilers and even fewer that have had new kitchens. Some of the Officer style houses are now occupied by SNCOs and a number have been allocated to Chicksands as the ones at Henlow are believed to be a considerable improvement over the ones at Chicksands. Overall houses aren't too bad and I believe they are all Grade 3 these days.
Henlow is a PAYD trial site but the less said about that the better.