Personally I joined the RPGA several years ago at GenCon UK in Loughbourgh, I then renewed my membership (for 3 years) at GenCon UK in Manchester.
Most of the RPGA tournament games I've played in or run have not been D&D, most have been CoC (Chaosiums version), Cyberpunk or Feng Shui.
Since signing up for 3yrs to the RPGA, the following has happened.
RPGA stopped producing Polyhedron UK, and instead went to a joint magazine with the USA, which obviously focused more on the US game scene and D&D.
The RPGA although promising to continue providing Polyhedron to old guild level members when it merged with Dungeon did nothing of the sort and now over a year (and several email) has passed without me seeing a single copy owed to me.
RPGA UK has been disbanded.
GenCon UK has been cancelled to become GenCon Europe.
Polyhedron has stopped supporting anything other than WotC products.
If you ask me the RPGA does nothing to support gamers, and just supports WotC. It use to be a great organisation in the UK and now it is nothing.