In my experience, dry-hopping is more important for aroma than flameout additions, unless you either go overboard with your flameout quantities or you do a hopstand. You may get a very slight bit more flavor out of a flameout addition, but my palette can't detect the difference.
During fermentation, the CO2 will carry a lot of the aroma with it as it escapes the fermenting wort, thus reducing the aromatics of the beer's hop character from what it was before fermentation begins. Especially for the Citra hop, which has a very distinctive aroma, your IPA will benefit from a good dry-hopping more than it would a flameout addition.
If you're looking for "the next steps" for your IPA, here's some advanced techniques for you to try out:
From my experience, Citra is a very pleasant hop to use, especially for the above two advanced techniques, as it does not impart a harsh bitterness at high IBU extraction. For my palette at least, I have yet to add too much Citra hops to an ale, so you can take comfort and likely not have to worry about overdoing it. Without knowing your recipe, here's a few tips I could recommend for your next experiment:
- (If it's an all-grain recipe) move your 60 or 90 minute hop addition (whichever it is) to a first wort hopping as described in the above article.
- At flameout, add your flameout hops, and separate a portion of the beer (could be a 50/50 split, or 75/25, whichever you prefer). Chill the separated batch as normal, but let the other portion sit and do a 30 minute hop stand at high temperature, as described by the above article. You may even consider adding another hop charge 15 minutes into the hop stand for an extra aromatic kick. Now you have a control, and a experiment sample to draw from so you can see the difference between hop stand and no hop stand.
- Dry hop both. If you want to go crazy, double up your dry hops, but layer them. Add your normal amount of dry hops, then at the 3 day mark, add the second set of hops and let them both sit until day six at which point you rack to bottles or keg for consumption.
The above will increase the amount of hops necessary, but as mentioned before, Citra is very forgiving if you go overboard, which I tend to with it, only to wind up grinning wider for when all is said and done. You'll know it all paid off when you can smell it across the room!