The Prime's basic range/mpg specs are a good match for my requirements, so I'd be happy with the current-sized battery. While I don't care either way about the fifth seat, what isn't acceptable for me is the loss of cargo space behind the rear seats compared to a normal Prius (or the AWD, which I looked at along with a RAV4 hybrid at the dealer).
While I find the looks of the Prime acceptable, I too would prefer the Gen 3 body for general utility. Unfortunately, the Prime would still be out for me as it still has the driving dynamics of a Prius, and while they improved those for the 4th Gen, it's only from abysmal to mediocre. What would best match my needs is a compact AWD CUV with a Voltec powertrain and 1/2 - 2/3rds of the Volt 2's battery pack. That doesn't look like it's going to happen unless Buick does it, so the only remaining affordable PHEV hope is a RAV4 PHEV, and it's unknown if they'll offer that with AWD.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].
The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.