Modem Pairing

I'm looking at the Motorola SB6121 vs SB6141. The first harnesses the power of DOCSIS 3.0 technology to bond up to four downstream while the second has paring/bonding of 8 downstream. I have 105Mbs with Comcast. The first goes to 160Mbs the second to 345Mbs.- both under my maximum.

Does anyone see any value in getting the higher SB6141? As long as my Comcast input is limited what difference if any would it make?

Thanks guys