Seems like a good size - I haven't cared for their "thinness at all costs" trend lately, as it makes the phone hard to hold onto. This appears to be much more hand-friendly.
I know they've improved battery life in the SE, but still, overall the trend is thinner with a smaller capacity battery (but more efficient components, so you ultimately break even).
I have a phone with a 3100 mAh battery @ 5.1" 1080p, it isn't the thinnest phone around, but boy does it last three or four days. It is super nice. We need more phones like that.
In contrast, if you charge your phone daily anyway, you don't gain anything by 0.5 days of added battery life.
Which one's that? Sounds like a dream phone for me :)