I am ordering a new bushmaster upper as soon as I pick a flash suppressor. I have NO idea which to choose; does anyone have detailed info that might help me pick one, or perhaps a thread that discusses them at length? I tried searching the forums but a billion query matches for “flash hider” discouraged me.

The two most popular are the Vortex and the Phantom.

The Vortex is a "prong" type suppressor made by Smith Enterprise.  There are a few versions out, and they are regarded as the best flash suppressors available.

The Phantom is made by Yankee Hill Machine.  There are also several versions, including a solid bottom type similar to the A2.  Performance-wise Phantoms are a close second to the Vortex.

Bushmaster sells the Phantom, and they will install it on your barrel for free if you buy both from them.  If you are getting a 14.5" barrel, they will permanently attach it without charge as well.

ETA:  Do a search on "Vortex or Phantom" and you'll find several threads comparing the two.

Thanks info M4-guy! I think I will go with the Phantom 5C2 Comp/Flash Hider
YHM-28-5C2.

Just a quick hijack here, how is the compensation functionality on the 5C2? Is it noticeable? Does in increase blast?

...and what're crush/peel washers for?

I can answer the third question; the washers are included to allow proper tightening of the flash suppressor while also achieving proper alignment, so the flat bottom is correctly positioned at 6 o'clock, and to provide tension to keep the suppressor tight.

I would love to here from anyone that has experience with the phantom suppressor/comp models as well.

I'll find out on Sept. 14th and report.