What's the best Operating System for mpc 1000???

i just downloaded like three new OS's, 3.08 4.99 & 2.12. Which one of these is the best and has the most upgrades? And what exactly are some of the upgrades and bugs fixed? thank

2.12 or 2XL.12?
http://www7a.biglobe.ne.jp/~mpc1000/mpc2500/chart.htm

read the forums for bugs if you're really interested. Not sure anybody has a handy chart for that.