My biggest problem with tie ins (as i dont have to actually buy them, which would piss me off) is inconsistancies.
Mostly, I'm sure editors or whatever catch these, however, A recent one pissed me right the F off.
In Punisher: War Journal 2 and civil war 6
Spoiler:
Punisher kills 2 supervillians who were trying to join the resistance movement.In War Journal, he kills them AFTER cap has shaken their hand, but in CW, he does so before any agreements have been made and while people are still negotiating it.
I honestly don't know which is the best representation of Cap or Punisher, I think for artistic purposes the scene in War Journal is far superior, but is only contained in the tie in.
Other than that stuff, I agree with most of the complaints and comments made about the marketing side, especially the comment about making the real series longer and better, rather than depending on the tie ins to tell the story. That being said, seeing the fallout of the events from the main title tied into current ongoings is very nice. 🙂