My phone isn't some entertainment device, it's a utility tool. I don't need it to be "smart", it should be useful on the go. The persona sketched by GP just isn't me: Messaging, maps, weather, 2FA, and calculator come first, email (read only) and news feed second, the camera is a third for documenting purposes (if even, I'd rather take my full frame). The easier it is to carry this thing around and the longer lasting its build quality, the better. Why would I pay almost double (USD 699 VS 399 on launch) for a less robust mini with sharper edges?!
If Apple were to continue the offer of rehashed designs from previous generations (preferably with rounder edges) for a SE line, limit its dimensions to never go beyond 140x67.5x8mm, and make it last for solid 5-year release cycles, then count me in as your most loyal customer. As it currently stands I'm looking out for a small sized phone from any manufacturer. I would even lower my expectations on support cycle and build quality quite a bit (if reasonable priced) before I'd give in on the size.
