We are currently preparing our Dufour Grand Large 380 (2014) for blue water sailing, starting with several months in the Med and a Transatlantic crossing. For her energy management (approx. 400 Ah batteries), we are considering a wind generator, in addition to a second alternator; so far, solar panels are also an option. We are excluding a diesel generator due to several reasons.
I would like to learn from others what your EXPERIENCES and SUGGESTIONS are with regards to WIND GENERATORS?

• power generation in relation to wind speed in "real cruising conditions"
• noise below deck - if installed on aft deck
• installation - physical considerations (e.g. space), materials, cost, tips & tricks etc. 
• maintenance
• comparison of brands (e.g. Superwind 350, Air-X from Primus Wind Power, D400 wind generator)
• benefits vs. risks
• ...

Looking forward to hearing from you!
Thanks, Vanessa

Thank you for your wealth of comments, sharing different perspectives! 
From all comments I take away that a wind generator definitely needs more than 10 knots of apparent wind to generate energy and that with regards to noise, it's about how I take it, but in an anchorage other sailors might have their own opinions about it ... It's interesting to see that if you had/ have a wind generator at all, you also have solar panels! 
@Dick I did not know of the AAC website and shall explore it now. 
@rhudson Richard, thank you very much for providing such a level of detail with regards to your experience - this is very helpful. 
@Nimue Anne & Michael, great to read that you tested all different types of energy generation and also mention the Watt&Sea hydro generator. Thanks for the offer to chat - I will send an email.