Honestly I think that either will be fine from a strategic perspective.
SLT seems to be the stated direction for ABAP systems and if you don't have ABAP then there is no reason why you would use SLT standalone.
SRS seems to have struggled to gain a lot of traction, due to license restrictions in the install base and SLT got a lot of development attention as a result. Recently, this has gotten better.
If you have a scenario where you will later mix ABAP and non-ABAP for replication, SLT will suit you very nicely. If you expect never to have ABAP, run with SRS - that's the best advice I can give.
John