I’ve obtained the Assimil latin sans peine course and the audio recordings seem to feature a rather heavy French accent - their "R"s are particularly prominent.
I receive the GREX emails, and occasionally write on the Grex. However, I think the Grex is dying. It has only 200 odd subscribers, despite having been online for many years. Compare this with Schola which has picked up over 750 members, with more each day, in less than 12 months. The political slant of some of the writing on the Grex has dismayed me, and I know others here on textkit have voiced similar views in the past, when discussing the Grex.
If you want to practice your Latin, the locutorium on Schola is a good place - you have real-time interaction. You can correct your grammar as you go, and talk about your latin, in latin, in real time. This is a very powerful learning tool. Schola is also a good place to meet people to initiate private Latin correspondence.
Most nights now there are people in the chatroom. The membership on schola keeps jumping - over 740 now, and a large number of these are professional academic Latinists, and there are a good mix of students, both tyros and advanced. You can get an idea of what people’s Latin is like, from their microautobiographia. Many members of the Grex are also members of Schola, so there is cross fertilisation between the groups. Schola provides the bulletin-board facility that the Grex lacks.
I think it is a great pity the GREX uses a listserve, as it creates a generation gap, as younger internet users do not even know what one is. The sooner they move to a more modern format, the better. Otherwise, they risk extinction or severe shrinkage, in the long term.
Metrodorus