I agree the handrail is quite 'bold' and I hate to disagree with my learned colleague (especially since I have no personal experience below 18mm), but I would be wary of angling such an UWA (10mm) lens downwards to achieve this, I fear it may cause all manner of problems with diverging verticals and barrel distortions. I would shoot with such a lens horizontal at all times (unless for dramatic effect) and crop as necessary to compose (I do this at 18mm on a D5000).
My thought looking at this was you'd done well to keep the horizon pretty level, although there is some evidence of converging verticals (so it may have been pointing up a bit anyway), but I think PP correction now isn't possible without spoiling the cloud composition.
It does look like whatever noise reduction you did on the main scene got 'missed out' on the water visible below the handrail though.
At the risk of appearing too negative, if mine I would be tempted to clone over the 'scratch grafitti' on the binocular viewer and handrail, even if limited to just removing any readable letter characters - although you may wish to include it as part of NYC culture.
I have fond memories of NYC (and USA), having visited back in '77.
Hi Donald, I know you have experience shooting with your 11-16mm, so if my advice to Aaron is incorrect/mis-informed, please do say so, I'd like to learn too.
Aaron, I hope that helps, oh and welcome to the CiC forums from ...