Upgrade from Thinkpad T460p to T480/T490 i5 Worth it?

I have a Thinkpad T460p (i7-6820HQ | 16GB RAM | 940MX | 1080P IPS) which works fine for me. I'm thinking about getting a T480/T490, but I can only find ones with i5 8th gen CPUs. Will this upgrade make a big difference? Any other models I should look at? Thanks for any help!