I've also heard about that some monitors freesync feature does work with nvidia cards, but mine isn't featured in the compatible list(vg245h).
So my question is what would be the better choice and why?
Does it work with HDMI? Since my monitor doesn't have a Display Port.You can use FreeSync on Nvidia cards now(the feature should work on every monitor, mine is not on the list and it works without problems) ... so I'd go for the 1660ti since it performs better than the RX 580 and 590.
Does it work with HDMI? Since my monitor doesn't have a Display Port.
Adaptive-Sync (FreeSync) technology supported within 40Hz~75Hz for HDMI port