I liked Royal Flush much more than Rhamadi Conflict, hoverver, I'm missing a real end for ArmA's maincampaign in them.
In the last mission of ArmA you find out that the King's troups are responsible for the masacre in Cayo but this part of the story get not continued in both campaigns. I think it's a bit pitty, but Royal Flush also has a really great campaign.
I really liked the story and that it's a bit like Resistance which had the best story I've ever seen in a game right after Cold War Crisis.
Of course RC isn't a bad campaign, however, I'm missing a huge story in it, but i also enjoyed it of course