Version 2005 would indeed be (two or three generations?) older than version 12. Version 12 was the first Music Studio version to actually be fully Samplitude-based, including the early Samplitude MIDI support (more than ten years ago). The version 2005 one still contains the "MIDI Studio" component for MIDI work, which was based on Logic and only licensed by MAGIX, before Logic disappeared from the Windows PC platform altogether. So, it stands to reason that it might have a few more things going on in the MIDI/VST department than older Samplitude/Music Studio versions.
Anway, both versions are pretty old and not suitable for current Windows versions. You might want to check out the information and free trial for the current Samplitude Music Studio 2020 on the MAGIX website:
I still use XP so will keep my eyes out for someone selling Studio 14 or 15.Studio 12 works great for me, but I would like to not have to transfer into my FL studio every time I need automation