I really like the duo because they're somewhat generic and not over-dramatic; I don't find they distract from the game whatsoever but have an appropriate level of enthusiasm; they're not trying to be the stars of the show.
Romo is by far the best X's and O's guy by a mile. It's crazy how many times he correctly calls a play pre-snap and does a great job explaining the coverage looks.
Collinsworth at this point is like a poor man's Romo, he can still offer excellent insight when he wants to, but more often is lazy and relies on cliches or generic statements that really mean nothing when you break them down.
My biggest gripe with both these guys is their enthusiasm for football and big plays sometimes doesn't comes across as impartial, to the point where it sounds like they're actively rooting against your team (this goes both ways). Also Romo still needs to develop a bit as an announcer (and I'm sure he will), and there's an inherent smarminess in Collinsworth's voice I can't stand.
Their play-by-play cohorts, Nantz and Michaels, I generally don't mind, although I do find both have gotten a little too colourful the past couple years, attempting jokes and analysis when they should probably just be staying in their lane.
I also think we all justifiably have a bias against Michaels and Collinsworth for bringing up the deflategate nonsense right in the middle of the Patriots (then) historic comeback in the Superbowl.
And yep MNF is an abomination, what a cliff.