Hello JWOP,
In our area here in Australia, each elder is assigned a Field Service Group. The Society recommends that each group be made up of 16 publishers max. The idea of maintaining the groups even though there is no bookstudy anymore is so that the elders can shepherd those in their group. They generally meet at the home of one of the members of the group, but there are always one or two groups that meet at the hall. The congregation combines once a month.
My experience with the group I looked after was that while I had 15 members, we only ever had a core group of three or four actually come out. Shepherding never gets done as there is no time or energy. The best most publishers get is the 'privelige' of working with the Group Overseer every now and then and getting asked 'So how are things with you sister?' . All in all pretty shallow and far from the rosy picture of what was painted when the arrangement changed.