There are some who know how to work through the OS boot limitations but I've never been able(more like.. didn't care to work that hard) to boot a drive that uses larger than the default 4k allocation anyways.. so as Nothinman already said.. it would be more for servers or such that need to be "tuned" for the majority of the file sizes located on the drive/partition in hopes that IOPS/performance could be slightly improved.
In the end all you really do is move the peak speed of a particular task or data transfer up or down the chart a small amount and you can't make a disks peak R/W faster than it is by design though. Not really worth much, if anything, for the typical PC user who wants increased performance from their boot drive and lots of testing would be necessary to realize the small gain to be had.
However, if you have larger amounts of vids/pics on a storage drive?.. using larger block sizes can help shift the peak transfer rates up to the end of the scales a bit for small gains. I use 16k for most of my storage arrays but you need benchmarks or a stopwatch to see gains as they're simply too small to perceive in usage.