ENO are offering dress circle tickets for the new Partenope at £25 (normally up to £84) via a promotion in the Metro.
You don't need to buy the paper, just enter the code PARTMET in the promo code box when booking online.
All dress circle seats are included in the promotion. Some are better value than others. Rows A to B are the only ones not overhung by the upper circle above, so these would be my first choice for sound quality. I would take front sides over rear centre. Legroom is not great anywhere, and Row A has the least.
**Update** the production has some (not much) action on an upper level. As the view of the top of the stage is cut off at the back of the dress circle, you might miss a little from here. But not much.