Unofficial vs official OS on MPC1000

Recently got an MPC1000, and I love it! It seems that most people install an unofficial OS on their MPC. Why? What's better with it? As an MPC noob I'm really happy with the one that followed!

Also, is it hard to install?

The free JJOS fixes some known bugs, plus adds a few extra features and changes others. Easy to install, easy to go back to the Akai OS if you wish. Give it a go - here's a list of differences:

http://www7a.biglobe.ne.jp/~mpc1000/chart.htm

Thanks, but is OS1 the free one?

No, OS 3.16 is the free one (referred to as 3.15 in that chart).