Existing active Support Contracts (TechConnect) allow free upgrade to V35.
Community consensus on Reddit's PLC forum suggests that v35.11 is the preferred stable release over the initial 35.00 version. studio 5000 version 35
:
Version 35 adds two user-requested instructions: studio 5000 version 35
for motion applications, users should note that older controllers like the studio 5000 version 35