From another thread, the filter caps aren't removed on the 2a, they are replaced with a different value so they don't clip the high end.

In my opinion, the only reason to get a 2a is if you somehow really need that extra RAM. And you wouldn't need it unless you had some sort of special custom software you wrote yourself that had to use it.

Otherwise, there's nothing wrong with the Mk2 units. And the little differences can be easily altered if desired (such as removing those caps).