Depending on how large your case is in width, the thermalright true spirit 140 power is likely the best single tower single fan cooler. Performs like an nh-d14 (even a tad better) for around $50 usd. The one glaring issue is it's tall so may have trouble fitting some of the narrower cases. It's 171mm tall.
Anwyay, it probably doesn't matter in the end of the day, they're so close to each other that it's extremely unlikely to make any difference to your final OC. Get what you like. I should concede that I really like Noctua as a company. They offer fantastic warranties, bundle their products with some of best fans on the market, and have a very good history of shipping out new mounting brackets completely free of charge to customers who upgrade their PCs and find themselves without compatible mounts.
They are expensive though, and give 0 choice of colour scheme for those who aren't enamoured with brown on beige. I'm sure there are lots of happy Phanteks customers out there too.
What, there seem a mistake in the site that you gave me the ph-tc14 is better than noctua nh-d15 by 1 to 2°c
I don't think I linked anything with a NH-D15 did I?
Also - I think you might be mixing your product names, the ph-TC14PE is the big brother of the TC12DX you're asking about in this thread. It's a massive dual tower cooler and competitor for the Noctua NH-D14 & D15 - not the single tower U14.
Depending on how large your case is in width, the thermalright true spirit 140 power is likely the best single tower single fan cooler. Performs like an nh-d14 (even a tad better) for around $50 usd. The one glaring issue is it's tall so may have trouble fitting some of the narrower cases. It's 171mm tall.