So, the only real advantage is the load times? I guess I am glad I did not get a bigger SSD.  Load times do not bother me, the actual gameplay is what I want to be better.  Thanks for the info. 

I believe for GC3 it won't be a big deal, but you definitely want to use SSD's for most gaming.

When I play Total War: Warhammer with my brother, it takes forever.  He's running on a notebook drive, I've got mine on a slow SSD, my map loads take a few seconds, his go about two minutes.  Our systems are actually close to the same age, his actual processing power isn't that far behind, but the dogshit drive makes for obscenely slow loading times.  Unlike GC3, these load times occur twice any time you manually fight a battle.  I've got a 2400MB/s drive in my laptop(which he refuses to use to play...) that basically removes waiting for load screens from the equation entirely.

Games are getting pretty damn big, so any of them that have frequent in game loading are really going to drag on you when your drive is only doing 70MB/s.

If the SATA drive is low quality, it can affect your experience playing the game.  Some HDDs "spool down" if they aren't accessed after so many seconds, and if this occurs you will get a lag-spike when the game tries to access the HDD and has to "spool it up" again...

I mention this only because laptops with a small SSD and large HDD tend to have cheaper HDD's to control costs...the solution is simple, you can get a program that just continually writes to a text file on your HDD so it never spools down, but if you aren't aware of the problem you might waste endless hours with graphics drivers and settings thinking that is the issue...

Well I've played gc3 on multiple labtops two without a ssd drive. The turn times on a ssd is noticably faster. What it doesn't increase is the number of factions.

It should run your 100 faction game. There will be a very noticeable performance hit with such an extreme game setting. As long as you are okay with that, you have got it made.  For me, the real problem is the Diplomacy window.  I cannot keep track of all those different people and I never know which ones to hate more than the others unless they are at war with me.

I had a HD only system earlier, meanwhile changed to SSD too.

Additionally to what others mentioned there's another point in the game where an SSD clearly pays off: on my old HD system there was a significant delay whenever I first called the ship designer - esp. when you selected to display all ship designs and all faction style modules. With SSD that's gone, and the designer comes up instantly