I bought the base pack, and am on their mailing list for updates - I'd expect them to patch bugs in any payware product, however humble.
As to upgrading to Block this or that, I've no idea what they left out of the base pack and why I'd want to pay for it.
With very few exceptions, I fly FS models by pressing <CTRL> E and seeing what she'll do.
One of those exceptions is the Aeroworx KingAir, and it is a doozie, you don't even get to see the MS GPS unit!
And I'll learn the SectionF8 Sabre too, because I know the systems are faithfully modelled and will reward you - if you use correct cockpit procedures.
There really isn't time to become current on all the stuff available, however.
But maybe the Capsim 757 is worth spending the time on, too...what's your experience?