Well first things first this is a very confusing issue many dont understand but I think I can explain it better, if not google is ALWAYS your friend! - I don't think people realize that with a simple google search they can answer almost any question they could EVER have in a few minutes and clicks
ANYWAY, there are different types of 4wd, there is permanent 4wd and part time 4wd that can be engaged manually on 2wd vehicles for low traction situation. The Jeeps are none of that with all of them being full time 4wdrivers which is basically what AWD is its all time 4wd with no 2wd option and o low range. The new WK2s have QT 1,2 and QD2 all with different options but all delivering 4wd of some sort.
QT1 is full time automatic 4wd with no adjustment needed with open diffs.
The QT2 has the 2-speed tcase and splits torque across the front/rear axels with traction and can send all power to axel with traction
And the Quadra-Drive 2 has the LSD and will detect wheel slip and distribute torque accordingly to wheel with grip. Both QT2/QD2 are similar and will act similar but Id like the LSD personally, preference will vary of course
And the SRT8 has none of the system used in the regular Cherokees as it utilizes a different LSD which works just like one above in the other GC's. It is considered an AWD vehicle in that its all automatic and there is no low range or 2wd mode w/ any switched needed to change torque vectoring etc. So the new SRT8 is AWD but its really considered full time 4wd. Personally it doesnt matter, just know all wheels get power and that it will thoroughly increase traction in low traction situations
and heres spec thread about SRT8 driveline
2012 Jeep SRt8 drivetrain specs, axles etc.