Re drive by wire, all the cars I have driven (except one) that have had it I didnt notice any weird behaviour, the Aurion for example still has very snappy response etc. A GT Liberty however, the power delivery varies significantly at different times, sometimes its great, other times its jerky and somewhat unpredictable. Not sure if this is the throttle or the fuel/ignition mapping (maybe a combination of both), but its annoying.
The other thing is that the GT Liberty (and some other recent Subarus I believe) also has a damper of some sort on the hydraulics of the clutch system. Its there so if you dump the clutch the actual clutch take up will be slowed to minimise the shock/stress to the driveline. The trouble is, the clutch pedal is completely lacking in feel and its take up varies from time to time, so its a PITA driving in traffic.
Hopefully the 86 wont have these issues.
Whether it will be the best fun for the money is more of a personal choice. Some people enjoy outright grunt and speed, some prefer response, feedback and nimbleness. Styling and practicality is another personal choice, whether you are happy driving a souped up version of a baisc sedan (eg WRX) or prefer something more uniquely styled (eg the 86) with more sporty lines.
Like my change to the WRX, it fitted my requirements at the time in being practical, relatively quick and a bit of fun. But like I said, it felt quite numb to drive and to me they are "essentially" just a budget sedan that is very capable due to the bits bolted to it. Without the boot spoiler, mags and bonet scoop, its a basic GX Impreza.
Cheers