Boot and load times are it. People will say it makes the OS feel "snappier" but unless you are constantly opening and closing programs or doing a ton of work with files it's pointless as everything is in memory already, and sleep mode loads quicker than an SSD.if you play games with a ton of load time it will help there as it will feel much smoother, instead of waiting on load screens, but otherwise just get one if you have spare cash. No point in skimping on the gpu to get one.
I would kill for one in my work laptop... Wouldn't do much but save a few seconds of map loading on my gaming machine