I've tried both Necro and Flawless and, for me, Flawless was superior. Better EPG, better stability, better quality. I only watched English content though, so no idea how they compare for international content.
Necro is stable but support is none existent
I work for necro and have a flawless sub...so, hahahaha!
Well, everyone knows about what happened with flawless last month, somebody did shit on their servers and they had a lot of downtime!
Anyway, get at least a month with each and see it by yourself ;)