Yes, 17G has a bit more spin and power and less durability. But, the durability should still be good with poly unless you are breaking 16G poly fairly often. I hybrid poly and the soft string always breaks before the poly.
The only downside might be 17G poly may not hold tension quite as well as 16G poly. But, I play all 17G polys and I play a lot of differenct Signum Pro polys - they hold tension pretty well - better than most.
Try it - I think you will it better.