6B & 6C is designated for passengers with disabilities. If they need to accommodate such a passenger, crew can change your seat assignment. 6D, 6E & 6F are not designated. You will receive a message online when choosing those seats.
"This seat is designated for guests with disabilities. If you select this seat, you may be reassigned to a different seat at the crew's discretion."
Rows 6-10 on the 738 are Premium Class and receive complimentary cocktails. Row 17 does not but you are still eligible for an alcoholic beverage in row 17 based on MVPG+ status.
James
EDIT: In row 6 there are only two power outlets on the back of the centre console of 3AC & 3DF for the three seats on each side of the row.