So I'm currently playing Fire Emblem Fates. I started on Birthright because playing that part after the other two would only highten the sense that it's a cake walk. I'm about twenty hours in and so far the obvious improvements over the previous game are mainly technical/game play wise.
Among the positives the pair up system now functions differently so you can either pair one unit wth another so their stats increase and your protected from some enemy attacks or you have the units side by side and they attack with you increasing the damage so its a choice between attack or defence also the enemy can make use of this system now so it's more balanced and not as op. And everyone has feet now so that's good.
On the down side I feel the story is somewhat lacking. After the action of the prologue style chapters and the interest of the choice which is the games central conceit the story slows to a crawl with most of it giving a little context to where your fighting followed by lots of rather mundane and somewhat banal character conversations which once or twice had been localized to the point of being cringe worthy. While it also features the constant introduction of new characters that is a common trait of the series they lack the range of background that previous titles posses with most being the royal family and their retainers, despite this some still posses rather interesting if under-utilised personalities. Again I must stress that I have been playing Birthright so any story complaints are limited to that version. Another issue and the only negative in the technical department is a less well defined map with no traversal, instead you simply select where you want to fight from a menu. This means that there is little to help illustrate where everything is on the map making it much less effective.
Finally a note to anyone that hasn't started playing yet: while the difficulty can be dropped in game it cannot be raised, a fact which is not mentioned during the difficulty selection and made all the more glaring as the easy mode has been labeled as normal.
All in all Birthright strikes me as boring despite the fire emblem pedigree which, as a fan, is extremely disappointing.