I wouldn't stress Immortal Servitude too much. Perhaps as a 2x, but no more than that. The real power of this deck comes from sacking stuff that you can do without to pump the other creatures and/or generate demon tokens (at least that's what the tourney winning version did).
I'd take elements of both decks. You definitely want to keep the Doomed Travelers over Azorius Arrester. It's cheaper and gives you two sack targets/chump blockers. When paired with Blood Artist and any of your sack outlets, more targets is easily worth more than the added one power and detain you get from the Arrester.
I'm hesitant to jump on the bandwagon everyone is on with Blasphemous Act to pair with Boros Reckoner - yes, it clears the board, but how often is it cluttered enough for it to be castable? (Mind you, this is an honest question here, as I don't know either way). Perhaps a cheaper option that does much of the same effect would work just as well? I know from some game experience that Rolling Temblor will often hit more than one target easily and can do serious work with the Artists.
Aside from those, you might want some added spot removal in the SB or to include some Cavern of Souls with the incredible rise in control decks. Boros Charm will let you survive a board wipe here or there, but if they counter your stuff before it even hits the board... well... then you have an issue.