I raid three nights per week with
Terror Australis. TA has been around on The Rathe for a few years now and although we consider ourselves to be a progression raiding guild, we do not have manadatory attendance.
TA plays in the Australia/Pacific time zone and so has mostly Aussie/NZ/Malaysian/Singapore and US military members. Like many guilds these days we have had to re-build ourselves a few times with people leaving over the years and so although we have killed Vishimta and are heading into the Demi Planes, we still farm CoA, DoN and PoR gearing up our newer members.
We have had to learn to maintain a fine balance between wanting to push ahead with progression for our core raiders and also keeping a "family/casual" atmosphere to provide a good home for people who play in our time slot. Guilds who want to survive these days cannot afford to be too restrictive, we have to recognise both that the player base is smaller and players are getting older and have family/work/business demands that cut into "EQ" time.
We get an average of 45 per raid night, around 30 of whom are always there on time ready to go, the remainder come and go as life permits. This makes it pretty tough for the Raid Council of course, especially when key classes don't turn up. To try to cope with this we recently introduced the idea of "Raid Helpers", these are alts of people who don't normally raid with 2 boxes, but who are willing and capable of bringing and alt 2 box along to a raid to help out. So on a bad night when we only get 30 regulars we can load up around 10 alt 2 boxes and still hit CoA targets etc.
Raiding guilds now seem to be a very different beast to what they were three or four years ago, but we are surviving and still progressing, slowly but surely.