The one thing that holds true in archery is personal preferrence. I used feathers for many years but lately, the past 10 yrs or so, I have been using vanes. I'm not a compitition archer, just a bowhunter.
Let's see now, feathers or vanes. It is true that feathers are lighter and more forgiving. As for quiet, it depends. I do no from experience that during hunting when my pant leg or limbs brush up against the arrow fletching in the quiver, vanes are quiter. During flight, feathered helical fletched arrows are noisier because the grab more air. Which isn't necissarily bad because they guide the arrow better. Also, feathers are alot more forgiving than vanes.
Vanes are a lot less expensive and more durable. Vanes tend to hold up better and perform better in wet conditions, also. As for the speed aspect, feathers are probably a little faster due to weight reduction. How much I don't know. I do know that helical, offset, or straight fletch are options with vanes but feathers require helical fletch.
As for helical or straight fletch, my personal preference is helical. I want arrow flight stability. A spinning arrow, achieved with helical fletch, is much more stable and accurate.
Heres a very good web site for info on arrows, fletching, etc. It should answer a lot of your questions. www.huntersfriend.com
Look under Articles and Help, then select Arrow Selection Guide. There are six short chapters on building and arrow. Chapter 4 has info on feathers and vanes.
Hope this answers your questions.