So, I've been lead to believe Structure Systems will eventually replace Weldments. I was also lead to believe that development on Weldments has ceased and all future development will go toward Structure Systems. I voted for an SPR on adding splines to Weldments, and they added it to Structure Systems and not Weldments. So, I have anecdotal evidence that this is the case.
What this means for you is that you eventually will have to move over to Structure Systems. From what I've seen Structure Systems will be able to do everything Weldments can do and much more. So, it'll be a good move when SS is ready for production use.
When I first investigated SS, I discovered a limitation that prevented me from committing to using it for production work (I don't remember exactly what it was, it may have been something like cut list items didn't get transferred to BOMs, or something like that.) So, this thread is here to point out what needs to be fixed before people can use SS for production work, or little things that need to be fixed with this tool.
When I get a chance, I'll launch SS and see if I can find the problem I had before and post it here. Please do likewise, as you find problems. And, let's keep it constructive.