I've actually kind of appreciated Iris on this show, and I find myself thinking she's written and directed pretty well. Now, that's probably because I went in to the show having a pretty clear picture of what she would be, and I was proven correct thus far. And this almost certainly confirms that I'm biased at least towards the classic archetypes, though I hope it's not a sign of me judging female character unequally to their male counterparts.
Some of you who are Arrow fans might know that I'm not a particularly big fan of Laurel from Arrow. That's because she doesn't fit the archetype I think she should have always been; that of someone who is clearly going to become the daring Black Canary from Birds of Prey (the version of the character I'm most familiar with), someone who's vivacious and tough from the get-go. And since Laurel wasn't that character for the longest time, I found myself aggravated at the lukewarm portrayal of her competency in dire situations:
I keep harping on it, but why in the hell did they have her pull a shotgun, then demonstrate that she only loaded one shell in it? Or how she's capable of some basic and effective self-defense moves against several villains, but incapable of beating a drunk guy when she jumps him with a baseball bat?!?! Be consistent, story writers: either make her a strong character who's competent at kicking henchman butt, or a classic in-over-her-head survivor! Don't show me one, then five minutes later completely reverse it!
In contrast, I figured Iris would be the classic Lois Lane/MJ from the Raimi films character: she'd be vivacious but not all that combative, and consistency written along the classic archetype's lines. And she has been. She's been largely defined by Barry's pining for her, and by her investigation and attraction to the Flash. And yet, the writer's have written her more consistently and competently in that role. We know she's going to talk back at Clock King but not stupidly confront him unless the situation gets desperate. Thus, while Laurel was usually written in Seasons 1 and 2 as a Faux Action Girl because the writers wanted a damsel in distress half the time, Iris is a classic Action survivor capable of pulling a surprise quick draw on Clock King.
So, yeah, I'd say Iris is a step up from Season 1 & especially Season 2 Laurel, but you guys do have a point about how she still seems just kind of there: we all know exactly what to expect from her 90% of the time, so with the exception of her shooting Tockman, we can all see exactly how her parts of the show are the "mandatory romance subplot" part. That does hurt the appeal of her character.
And in my opinion, the best female characters on Arrow and Flash have been the ones that have organically grown into their roles, the ones that were disconnected from the long term plan in some way, so they could expand naturally. Moira, Sara, and Felicity all wound up being defined more by the skill of their actors and logical story progression, and all are excellent characters because of it. This may be happening to Cailtin right now; she's got a future in mind, but it's far enough away they can just focus on making her a cool character.