Disagree with the above, as your army is clearly attempting to maximum potential out of Standard of Devastation.
First thing to note is that the Command Squad can have 2 extra Black Knights due to this Errata /
FAQ:
http://www.games-workshop.com/MEDIA_CustomProductCatalog/m3180051a_Dark_Angels_v1.1A_APRIL13.pdf
I really dislike the Champion upgrade in
RW or Greenwing command squads (although the
DW one is awesome), but that's personal choice.
Look at some Power Field Generators. They're great in the command squad because it's going to be attracting alot of attention and more reliable than hoping on Forewarning from Divination. The invulnerable save will protect you from Heldrakes and it's another thing to stand you apart from a White Scars army.
I'd avoid the Dark Talon, getting it within SoD range (measuring to the Hull) will block off your own units and is really a one-trick pony (going into Hover mode to get a second turn with it will see the Talon destroyed with ease). There's some argument to the Nephilim against lighter aircraft, but against the scary stuff (Heldrakes, Storm Ravens etc.) it's unimpressive and overpriced.
If you decide to go with Black Knights, you could get command squads instead. They'll cap out at 5 instead of 10, but are 2 points cheaper each and have access to an Apoth.
Beware of First Blood with the Attack bikes though.
{Edit} +1 for the thread title though