The midship angled balconies have a LOT more space - about double. I had E410 in January. That is an obstructed deluxe balcony on Emerald Deck 8. The "obstruction" on both port and starboard for cabins E409 - 412 is only that below you on Deck 7 there are outdoor dining patios both sides. Both are covered with white canopies. You have an unobstructed view to the horizon. On our cruise, the obstructed deluxe was about $500 cheaper so to get the extended balcony thrown in was a bargain. I strongly recommend looking at these four cabins - added bonus of a nice stable, convenient midship location only one deck above the Promenade deck. Obstructed view cabins forward from this location will be obstructed by lifeboats and/or machinery. You can't see the lifeboats from the cabins I mentioned because they are on the outer edge of the "crescent" portion of the ship, so you are angled towards the opposing edge of the crescent.
Of course, if you want to be higher up such as on Deck 9 (D409 - 412), the balconies will be exactly the same.