All these groups really bug me, i hate the fact they are e-mail based rather than internet forum based as my e-mail isn't great. When i first got online it was Mil Air uk and Scot mil, now there must be loads, i just gave up with the others and just still have the two mentioned.
There are far too many groups these days. Most quickly build up numbers of members but very few members ever post anything. Looking at the lists of members they all tend to be pretty much the same people on each group and strangely enough I don't see many of the people I've built up friendships with from 30 years of airband listening.
(I know I'm slightly guilty of that here - I'm not currently in Cumbria but am always willing to try and help out by chipping in on the wider areas of radio equipment, freqs etc. as I've been playing radio for 30 years)