I joined the Guild a number of years ago and was an active member on the policy front. I was fortunate enough to represent the UK on one of the IFATCA committees. On this committee I was tasked to write a couple of technical papers each year. As I sat on the committee for 7 years I was involved in a diverse range of topics and really got to broaden out my knowledge of ATC / ATM. I have no doubt that the knowledge that I gained whilst 'working' for GATCO / IFATCA has benefitted me in my day job and I still call upon knowledge acquired in my time with the Guild from time to time today.
I also got to visit many differing parts of the globe, made a number of good friendships and even presented before a Parliamentary sub-committee.
You can really benefit from Guild membership and the more you put in, the more you will get out.