Yes drafting, Zwift calculates your speed using your height and weight (and which in-game bike and wheels you select). When you get behind another rider (closer more draft) the trainer resistance is decreased. The larger the group the bigger the draft. This is why the Team Time Trials are so popular. Likewise when you have a gradient change the trainer resistance changes giving you hill the climbing experience. Sometimes its brutal but you can also coast downhill. Try the replica of Alp de Huez route or the Yorkshire Harrogate course where the current Worlds are going on. You'll find its really realistic. Wind? No, but they can easily add it if they would like and probably will at some point. This is a popular request by a lot of Zwifters. They introduced steering in a beta form at this years Eurobike. They have added a new route about every 6 months for the last couple of years. There are currently over 100 miles of roads in Zwift and the plan is to have 1000's. The whole thing is quite amazing and fun to watch as it expands. You can free ride, do trainer road type workouts, enter organized races, or group rides. Races and group rides are going on almost every hour 24/7. The community is a lot larger than many realize.