Hi Bob ,
SAP Open Text is good carrier wise but you cannot make career in Open Text without career in SAP.
For knowing Open Text , you need to know SAP first .
Yes. SAP Open Text requires knowledge of SAP ABAP and Workflow .Most of the time ABAP is used in implementing User Exits and BADIs while working with Open Text.
Open Text have good future , if you know Open Text , automatically you know about SAP Data archiving which is an emerging market now as most of the companies is having SAP for many years now and to manage the daily growing data , more and more companies are going for Data Archiving solutions .
Hope this helps .
Thanks
Manik