Upgrade to XB6 from XB3 or not?

Comcast sent me an email yesterday saying they gave me a speed increase (which they did months ago) and I needed a new device to take advantage of these increase speeds. I'm in the signature tier and was boosted from 400 to 600. My modem is the 3941T and using the Ookla module speed test I get 600 during the day and 640+ late at night hardwired to my computers. My cellphones over 5Mhz connection get 100 but that is limited by my phone. My new Samsung Galaxy Tab A Tablet with OS 9 (Pie) gets 223. So do I need to upgrade to the XB6?

I like the 3941T because it gives me 4 hardwired ports. I currently use 2 and if I need another it is there while the XB6 only has 2 hardwired ports. (I guess I could use a switch in an emergency if I needed to hook up another computer.)  I also get 16 wifi connections of which I am using 7 now. I assume the XB6 allows the same number or more.

So what are the pluses and minuses of switching over to the XB6? Anyone wish they didn't upgrade to the XB6? Thanks for the help.