I SSD'd an old-ish laptop I bought as a refurb about 3 years ago - it's still brilliantly fast now, and I haven't even had to reinstall Windows!

Just bought 2 mini PCs from a Chinese supplier (via Amazon, not personal collection, more's the pity), both with SSD, they're like rocket ships compered to the more leisurely standard HDD affairs.
One thing to remember, SSDs have a finite lifespan of writes, unlike HDDs which either die young or live forever...