phpBB is user-friendly, which counts most in a retired-expat community. People are used to it, can handle it easily. Apart from that, there are upgrades available which include more features by the time. phpBB3 for example seems to have just about all features. phpBB2 can be upgraded to it, when it is finally released. Members can get used to it slowly, no need to use all new features. It will not be completely different software.
New forums have the problem of attracting new members, if they use software not common to their target group. Building up your forum first with quality content does not depend upon the features but more upon people being familiar with the software.
Spam-robots are certainly a problem. The visual confirmation check is about useless, hopefully improved at phpBB3. But at MyBB it does not only keep Spam-robots away but also people who give up after a few unsuccessful attempts.
If you haven't got much time, and want to see what the new phpbb3 can offer, just try it out on this host : create forum
Hope this can help!
