Solid state drives are infinitivly better then Hard Disk Drives.
They're faster
you'll see load times and os boot times increase by up to 70 % vs HDDs
They're reliable
Unlike HDDs which have moving parts, SSDs do not have any moving parts and will almost always arrive without defaults. Where as the HDDs run into so many problems, being moved around in a truck. You're paying a lot more for an SSD, but you can almost guaranteed it will work upon arrival.
They're smaller
without moving parts, they can compact the storage device into a 2.5 " drive bay. where as the HDD takes up a 3.5" drive bay.
They're silent !
No moving parts = no noise
They use less power
They don't use as much power as the HDD, thus extending the life of your power supply.
They don't generate heat
No friction inside of the hard drive, so no heat is exhausted
They're lighter
More portable then an HDD, SSDs can fit inside of your pocket.
Relating the topic, I have my os and league of legends, along with all of my driver updates on my SSD, I keep steam games, pictures and such on the mass storage HDD, because when that breaks, I can always re-download my stuff, where as drives and such should be kept in case of a faulty drive version.