I like to try things that are a little off the beaten path. I shoot an off brand bow, hunt from a tree saddle, and now I shoot FOBs!
I killed two deer this year with the FOBs. They fly great for me out of my setup. You do need a well tuned dropaway rest to get them to work. Any contact at all will be a problem. I use a QAD Ultrarest Hunter, and it took me a little bit of trial and error to get the proper drop. Now it works great. Once your rest is set up, you can't beat them for arrow flight, especially in a cross wind or with a big broadhead.
I hate fletching arrows, and the FOB means never doing that again. They take about 3 seconds to install. And you can save money by buying bare shafts instead of fletched arrows. One bad thing if you shoot 3d: Your buddies will love busting your FOBs! And you don't want to shoot groups either.
On a passthrough, the FOB pops off to allow the arrow to continue through the animal. I've found that you need a white arrow wrap in order to see the blood on you arrow, but that's no big deal. It's also easy to see your arrow in flight. The FOB is very visible. I shoot the orange ones.
After a while, the looks will grow on you.
As far as noise, there is some but you can only hear it from behind the arrow. I'd say there about as noisy as feathers. Not bad, but I did notice it. The deer didn't hear them because they didn't duck at all so I don't think it's anything to worry about.
I also like how they provide an additional anchor point. At full draw, I can feel them just barely touching my chin, which I think can only help accuracy. It's like a kisser button without the added weight on the string. Depending on your anchor point, or if your draw length is too long, the FOBs could bother you. Most people have no problem.
They are pretty inexpensive too. For $20 you get 13. My shop charges $2.50 an arrow to fletch, so I don't think the price is bad at all. The nice thing is you can take a FOB off one arrow and put it on another arrow (unlike fletching) so 13 FOBs will last a really long time, if you don't shoot groups.
I did have one pop off while walking through the woods. I was walking fast through some very thick brush. That nock fit a little loose so I'm sure that had something to do with it.
Hope this helps. I tried to be as objective as possible.