Keeping this simple for the RV crowd...
SSD has 3 main advantages:
1. Faster - transfers happen at near the speed of the SATA interface.
2. Durable - no moving parts
3. Uses less battery
The main disadvantage that everyone knows about, is cost.
Another disadvantage that I am seeing is they rarely warn you when they fail and when they fail it isn't a simple put it on another computer and run a recovery program to try and recover things. Most of the time they die completely, just stop working. This isn't 100%, but in my experience it is pretty close.
Also worth mentioning are hybrid drives. Hybrids are both SSD and spinning disk. They are more durable than a pure spinning drive, but not near as durable as a pure SSD. They are almost as fast as SSD, and offer large capacities for a low cost.