Elektron Musical Instruments

Hi,

I'm considering to by a used machinedrum. I know that serial number 
of MD is 44, so it is one of the early units. I read from Elektron 
website that I could get new knobs and outputs for it free and it's 
pretty cool that they do this kind of service. Now I'm wondering if 
the early series units has some other things I should know before I 
buy. Any differencies? Maybe there will be some issues in the future, 
I don't know...

Toni Ahvenainen.