You need to buy JJ OS1 first for $49, enter the password. Then, revel in all the glory of JJos Version 1 and how it dwarfs Akai OS and the free version.
Next, you install JJOSXL (or OS2) for free. Try it, if you think it's worth $64, than buy the upgrade and enter password.
If not, then keep rockin' beats with OS1.
I bought OSXL one day after buying OS1 based on the feature comparison and haven't looked back. Having owned my MPC for only a few days before upping my OS, I essentially learned the MPC1000 using JJOSXL and don't have any complaints. 32 audio tracks is friggin awesome! Arpeggio is good as well. I figured out most features within a few days and have rocked some of the tightest beats of my 12 year music production career.
Some features do change location or methodology from OS1, like the Q-link mapping to TC Swing, you now can only use Q-link for swing in Drum Grid, not a big deal (especially when for 2 days I thought one of my most used feature was lost!!)
Buy it! JJOSXL. You won't need another MPC for a while (did someone say MPC 9000?).
Erik