More importantly, which has the better software framework?
The X72 has better overall, full load performance. The H150i has a slightly better noise profile and lower overall noise levels.
The NZXT CAM software on the other hand is a nightmare of rarely working wonder. I've been using various CAM versions since it's inception with Hue, Hue+, Grid, Grid+, Grid+v2 and various coolers and while it mostly works ok some of the time, there have been a LOT of problems with it AND maybe the biggest problem of all is the well known fact that it has a significant CPU and memory footprint due to the fact of it's information gathering phone home practices which have been well documented on both Reddit and the CAM forums.
Corsair had a lot of troubles with it's Link software in the beginning but those issues and any subsequent flakiness have pretty much all been worked out. I haven't heard any complaints or seen any issues with Corsair Link based hardware in a long time. And to be honest, I'm not a fan of Corsair, and I like NZXT products, but having good hardware is practically a moot point when your software is as quirky and riddled with privacy problems like CAM is.
In all reality, either of these will work great, if you don't mind the occasional CAM bugs which tend to happen every time there is an update to the software and then last a while until the next update, which tends to introduct new problems but resolves the old ones. Sometimes. LOL.
Personally, I don't think I'd choose either of those units.