Remember that when you are trying to decide for a GPU, there are two important things that you need to consider.
1)Your taste of gaming
2) Your monitor quality
I am personally using 1660ti because my taste of gaming really demands ultra settings on every single hardware-demanding game. (1920x1080)
Before I start saying anything else, If your monitor resolution is above 1920x1080, gtx1660 wont be enough. You'll need the ti at the very least
If you have a default monitor 1920x1080, and If you are playing standart games, and you're fine with medium-high settings on all the hardware demanding games, gtx1660 should be a very decent choice.
So ultimately, remember that the question "is it worth" depends on your needs and your interests, and your monitor.
In your case, its worth in these scenarios:
a) if you have a monitor above 1920x1080
b) if you want ultra settings on every triple A game
Its not worth if
a) you are only playing games like LoL, CS:GO etc etc.. non-demanding games
b) you are perfectly fine with medium-high settings on TripleA games such as assasins creed origins etc.