sorry for the alphabet soup. Should have been more specific.
I am glad I am not the only one to not be able to make sense of the options they offer.
$370 for the 4 computer one is simply too much money for software that someday could go unsupported.
$160 for the platinum seems reasonable.
Just didn't want to buy it to find that it only works with one extra computer.
A midi interface would be cheaper.
FWIW, I bought the Standard version ($129) and it works fine with my four computers (MacG5 sending MOL to 3 PCs, simultaneously). I don't really know what the "up to 4 computers" is all about, but if you look at the "purchase products" page of their website, that is only stated in the bundles section. What is bundled, I have no idea, but as I say you should be able to do what you need to do with just the straight CP Standard version...unless they changed it since I bought it which was about 8 months ago.