I used to do similar for a programming language, but it was around 30-40 attendees. Stayed at a hotel which had a large room with whiteboard, table and chairs so at to be arranged as required. Mainly run as a training event and attendees volunteered to show how they tackled problems or met requirements, so it covered everything from transitioning database files from ISAM to SQL variants, learning COM objects, creating own controls and more and was windows based. It proved popular because all presentations where submitted before the event so the powerpoint presentations could be stored on a cd/DVD along with their notes and example apps. This was so that if you were at the back of the room you could still run through on your own laptop what was being shown on the projector and also allowed you to work at your pace whilst also having something to take home with you. Some people learn from being tutored (theory) others learnt from the examples (practical), and most learnt from a bit of the both. Having attended virtual online remote conferences, you dont get the same networking & relationship building as you do with the in the flesh conference which is important. Virtual conferences dont allow for the chit chat that you get in the flesh and this aspect of networking is hugely understated. It can build life long friendships and working relationships whilst also being useful for planning what to discuss/be taught in for future meetings. Whether its as relaxed as the type where one goes skiing is upto the group but having annual or biannual get togethers in the flesh is so much more productive because you get the spontaneous chit chat, inspiration that you miss from the sterile online remote conferences, not to mention the ability to pick up the phone, drop an email to ask someone something during the months between the meetings.