Obviously keeping the files on the local machine would benefit from less wait time during the mirror copy process at boot. The PRO's of this would be self evident when you take into account the more premium speeds of RAM and the latency compared to a HDD. You could still have a RAID0 Game HDD config with 128kb stripe size or you could go extreme and use you're carefully planned local network storage to keep the main data, with the excess ram you could use the RAM to launch the stuff you actually use on a daily basis. The cons of such is that anything stored on the RAM Drive is lost when the system is powered down so to prevent this I would use an alternative method instead of backing up what was on the RAM Drive I would instead use the the Physical Disk HDD as the main storage for the games then when the system boots up it would run a script to mirror latency sensitive games such as MMO's and Skyrim generally a couple of Games you often play the most to the RAM Drive and then launch the games from the RAM. You might want to keep 16GB dedicated to the system which is abundant for most of us but with 32GB or even 64GB the rest of this can be utilized by creating a RAM DRIVE. The potential is there and is no longer a pipe dream of the yesteryear now that consumer level has the capacity to support daily use of an alternative such as this which was previously reserved for latency critical server workloads.
I see that having 64GB of ram as having alternatives to using another SSD and being able have slower cheaper HDD storage with the data present on physical disk which is then is selectively mirrored to one or more RAM Drives created using excess Physical Memory. My opinion to this is while people generally buy RAM in amounts that are what they would need with some extra left over, I look at it with a different view. We all know that RAM-DRIVE's are not new, but with consumer level equipment getting cheaper per GB and RAM being available in excess of 32GB for most modern motherboards where does that leave us in terms of storage options.