Id personally much rather it work like Landslide via an avatar flying and doing the damage. Id like to see what people think about this? Would you rather:
Keep Deep breath as it is.
Have Deep Breath be like Landslide without having to fly yourself and use an avatar flying in the direction you send it.
Something else, but not the way it is now.
I think it does way too much damage to be 1 global fire and forget.
Number 3 for me.
If they ever were to rework it completely, I’d prefer them to do it like in one of their previous concept art showed in the Scalecommander thread Feedback: Scalecommander in The War Within - #38 by Sithalos-malganis
This would give players more freedom and control over where you breathe. Depending on how they do it, it could also remove a lot of the clunkyness from the line targeting it currently has.
I like it as is, with the exception that you hard commit to your destination after casting. The talent in the scalecommander tree to allow you to turn while flying will be nice and offsets this issue, so personally I’d prefer it to not get drastically changed
I can’t really see the steering changing much. (You certainly won’t be able to do donuts around a target to get the full Deep Breath on them unless they have a mega hitbox), I feel like it’s more going to be a slight steering to dodge aoes and that’s it.
Honestly i kinda like how it works, that is coming from a pvp perspective though. I rarely use it just for damage, its more for the stun and the damage is a bonus. There are even rare occasions i use it purely for the mobility. Its also great against rogue in arena, is you deep breath towards your healer as soon as he gets sapped there a 95% chance you hit the rogue out of stealth because he’s coming straight to you. i can see how in pve it might not be great but personally i love the utility of it.
Deep Breath feels awful to press. Even if it’s strong, it’s not fun. Having a Hero Tree based around it will only make it worse.
Ashthal already linked my suggestion for changing it.
Gameplay should always come first. They can dial-in the damage after the fact. If they turn Deep Breath into a CS window with a heavy DoT, and an optional talented stun, that’s more than okay with me.
I agree that Deep Breath, as it currently is, is pretty nice to use in PVP scenarios. I especially love doing it in Epic BGs like Ashran (can make a big difference in a fight with the stun too)
I think deep breath feels great to press up until the point where you get yeeted out of the sky by flying through bad. Prior to this hero tree, I just wished that there were builds that utilized it more. Unfortunately, imminent destruction lowkey sucked and the talent trees kind of pigeon hole you into 1 specific build to stay versatile.
highkey sucked*
I like it when it works and I’m not unsuccessfully spam clicking the ground trying to make it work.
I often have “no path found” issues with Deep Breath, e.g. at the last trash group in Waycrest.
Blizzard should consider reworking Deep Breath to work like Flying Serpent Kick of the monk, first click to start, second click to land. That would also make it easier to implement the Deep Breath Hero talent in TWW, where you can navigate while flying with Deep Breath.
I second the notion of wanting them to fix the “no path available” nonsense, it’s literally lost me games in arena because my character stood there staring at the kill target instead of following up on my fdk’s go because for whatever reason it’s too hard to code a line based ability that lifts you off the ground.
I do not LIKE deep breath at all. It does not feel good to press, yes the damage and stun are nice but the actual button and animation does NOT feel good. Landslide however feels amazing! I would like deep breath to do what op said and just send a mirage forward and maybe u can tp back to the start position or tp to the mirage’s end position. 
Deep Breath, Dream Flight and Breath of Eons should just do this, let it send a Time/Sand clone and at the end of its path it lands and lets us use recall basically in reverse.
Instead of Teleporting to the place it begins with we can recall to the place it ends.
Seems so much easier then putting ourselves in harms way, also lets us continue to dps/heal with no interruptions.
I like flying with Deep Breath.
A main goal of the introduction of Dracthyr was to let players “play a dragon”. While Dracthyr aren’t exactly big dragons, they do have a number of attacks and abilities that do a great deal towards helping the player feel like a dragon.
Deep Breath is one of those.
That said, it can be a bit awkward to use.
My recommendation:
The problem with this is that oftentimes the reticle is the only way to reliably (insert air quotes since that’s still not reliable) know where you can use it.
I’ll be interested to see if the Maneuverability hero talent allows you to just use deep breath like a monk serpent kick (in terms of how it activates). I’m not sure why this wasn’t the original design intent to begin with.
If I could just press Deep Breath once, and it worked, I’d be happy. I hate mashing it and hoping it’ll work eventually. It should work 100% of the time on the first press.
But yeah, the best option would be to change that talent that recalls you. Instead, it could be an option to send out a clone. So you could choose which version you want and it makes the talent more appealing.
With the @cursor macro, if in doubt, move the cursor around the approximate location you want to Deep Breath while spamming the macro hotkey. This gives you multiple attempts to cast Deep Breath all in less than a second.
I don’t think the pathing issue with Deep Breath sometimes not working will ever be fixed. Mage Blink has had the same issue for the entirety of WoW’s history. Despite constant complaints it still hasn’t been fixed even after 20 years.
Or let it work with @cursor or people can just use it like it is now. It can be a choice.