In my experience the forward cabin tends to book up before the rear cabin - try looking up the flight on expert flyer on dates over the next 2- 3 weeks to confirm . Having been in both there is no difference although the forward cabin might be missing centre overhead bins. I certainly wouldn't pay in advance to be in one over the other. The rear cabin is often?/ sometimes held to allow the forward cabin to disembark 1st so if those extra 30 seconds at arrival are vital I'd suggest row 7. As far as conversing with your travel companion goes, CS just isn't that well set up for it. The centre seats are angled such that each of you are closer to the aisle than to each other and you have to lean quite far forward to see through the open partition. This combined with the high level of background noise means that after a few strained attempts you will likely just opt for the ife in your private little cubicle.