I have a WH11 Gen3, so do 2 others in my street, the same color, Tungsten!
Mine's the only one with a sunroof though!
I haven't had it that long, but, I love it ! Best I've ever owned. (once had a HT 307)
The engine problems you refer to were an issue with early Gen 3's, but the problem, too short piston skirts = piston slap, surely would have surfaced and been rectified if the motor is over 100,00 k's? ( don't quote me) The tuning is all electronically controlled, of course, with an "optimum" stock engine performance tuning available as a cheap mail order product.
Modification of the engine might not be needed at all by some.
It pulls and pulls and, then hang on, it pulls more...
Very well designed motor. And extremely easy to get parts for. Ever tried buy parts for a motor that's fairly scarce and in demand?
1st stage of engine mods, OTR and throttle body are cheap and don't cost too much, earn you 7-10 kw, + Full house exhaust, upto 20 kw with mafless tune.
Intake, rails and injectors up to LS2 spec, around 25 more, (with another bloody tune!!)
While a lot can be said for an extra 50 kw; that's about $3,500, if you install, and you still have to pay for all the bloody tunes!
If I can just get a OBD with software working THAT wont be such a problem anymore!
Electrics haven't been a real problem, replaced an oil sensor.
The problem is not being able to recognize the DTC codes.
Once you know where to start looking...
I have had a Holden mechanic hook up a TECH2, diagnose the wrong problem, and leave me prepared for a hefty bill. But that can happen with any OBD car... Thank Christ I found out it was the Alternator overcharging.
Roll on real time console mount OBD dispaly.
Most mechanical issues seem to be the same as any other commodore model. Drop it on it's guts and you'll be needing a camber kit. same=same
Immense mid to high range torque, even for an old Barge... Can be known to leave others behind looking silly, cause its only a Stato?... LS1 heaven.
If you can find a Caprice, do so, just cause they have the "LUX" drivers memory seat,
and if for nothing less, you can say you have one...
But then, should you find a Grange,
grab it, even if it's to sell to me!
As you can tell I love mine, and for what you can pick them up for now, I'd recommend you do... you CAN be choosy. (As long as you dont mind Tungsten!) 
Of course, by my username you can see I am one-eyed, Hope my bias didn't cloud my judgment too much. And of course, please don't take my comments as gospell!
As said previously there are others who are probably more qualified to respond; I just thought I'd put in my two cents.. Good Hunting.
Statesmad
... You funny Guy, I like you...
I kill you last...