Well, to add a few technical pros/cons, lets start with what I understand to be true off the top of my head. I'm sure some of what I think to be true is debatable, so here we go.
1G: Pros - lighter, came with bigger turbos, nearly inestructible suspension hard parts(A-arms, chassis hardpoints, etc), better visibility for most drivers, stronger/more solid unibody, early 1G's had 6-bolts, late 1G's had 4-bolt rear end units, a small number had both, greater variety of models and body styles, greater variety of engine and trim level options, much less expensive, high prevalence of eeprom ECU's, more aggressive heads and cams (except 90's), much more aggressive timing and fuelling curves, bigger engine bay with more room to get at stuff, much more likely to have LSD (on AWD models).
CONS - less ergonomic interior for most, more likely to have bad paint, that nearly indestructible suspension is HEAVY and reacts more slowly than a 2G, early 1G's had flimsy 3-bolt rears, late 1G's had 7-bolt motors, harmonic balancers are more prone to delaminating (falling apart) than 2G's, turning radius of a full-sized truck, less efficient intercoolers, restrictive exhaust manifold, turbine housing, and O2 housing, ECU capacitor leakdown problems, leaks/wind noise from sunroofs, rear hatch struts that collapse/wear out quickly, horsecock shifter, floating windows don't seal well, open front diff in all models.
2G:Pros - More comfortable/ergonomic cabin (for most people), cosmetic appeal (questionable), more aftermarket support, more efficient head design for fuel economy/low end torque (stock form), smoother turbo spoolup (stock form), much faster engine management with more safety features, better crash-test ratings, nimbler suspension, bigger/freer flowing exhaust components, lower Cg (aerodynamic drag), greater stability, more rear seat headroom, all 2G AWD's 4-bolt rears, better fuel efficiency, higher base HP/torque, bigger brakes, more efficient intercooler, much improved MAS, quieter interior and quieter outside, kickass audio components stock, really cozy seats.
Cons - front seat heardoom-especially with power seats and sunroof-is rediculously less, big blind spots on both rear corners, she got FAT! (all exterior dimensions increased), lost some ground clearance, big increase in base weight makes the 2G SLOWER with similar options, despite 20 LB/ft more torque in the turbo models, less likely to get a factory LSD rear, tamer fuel/timing system protects engine at the expense of performance, the more efficient head and intake is also more restrictive and limits top-end gains, the nimbler suspension comes at the expence of strength - much more likely to knock a 2G out of alignment or bend a suspension piece than a 1G, doors weigh a ton, floating windows don't seal well, wind noise from sunroofs, premium sound system components are freaking HEAVY, power seats weigh 80 freaking pounds, the softer vinyl of the bumper covers makes it easier to survive a bump without going to the body shop, but they can also mask damage that needs to be prepared, less room in the engine bay, motor/tranny mount system improves rigidity and control responce but makes maintenance on tranny or engine parts a bitch, no chance of an external oil cooler, underszed turbos, nonturbo models stuck with a Dodge engine which makes cross-model support really poor, automatics suffer from the increased weight of the vehicle and need expensive modifications to hold a realtively average increase in power safely, open front diffs in all models, and the greatly overhyped problem with thrust bearing failures approaching almost 1% of the Mitsu 4G63T blocks between 1995 and 1998.
Ok, them's my observations. To me, it seems that Diamond Star didn't know what to do with their little firecracker. When the time for revisions came in, they softened and fattened the little psycho into a chubby prom date. Still a great performer - but softer, more accessible, curvier, more eager to please but at the expense of raw thrill and brutality. They were chasing the money that was just a little more timid, that didn't like a turbo to come on like a freight train, that didn't like the ass end to drop down and wiggle all over the place on a hard run. And, they got it. Got enough of it, that Mitsu started to believe their on hype and priced the late 2G's out of the market segment where they could best compete.
Next player? Anything to add or debate?