Thanks for those great and very helpful replies. I'd also referred to ET's own seat maps and it seemed to be that Rows 17 or 18 were the way to go. So seatmaestro.com appears to be pretty spot on in its recommendations for this aircraft. Row 18 (despite caveats) it is!

FWIW, I was a bit surprised that despite having no status on Star Alliance, the reservations agent allowed me to select an Exit Row, extra legroom seat.

Thanks again. You've been really helpful in this and another thread I started.