I'm getting a 37-38 mpg mixed driving in and around London/Kent, just a few mpg's better than both our 1.2's over the same trips.
On a long motorway/fast A road run I get 44-45 mpg out of my TA 4x4 without really trying, which is a little less than the 1.2's manage on a steady run.
Have some fun and hammer it down country lanes, low 20's if not 20 it's self, quite a lot less than the 1.2's!
They do drive better and give better mpg if you ignore your natural senses and hang on to higher gears as long as possible, even though it sounds and feels like you're flogging the engine to death.
This can make them sound and feel a bit juddery, breathless and you can often count/feel each piston stroke, but the turbo soon spins up and it's back to it's normal mentalness.
They do require a lot of cog swapping around town, first gear is painfully low and it's very easy to spin up the motor and hit the rev limiter and look like a right plank without troubling the speed limits.
You can get them off the line in second, but you do have to abuse the clutch a little, best just to get them moving off in first and short shift into second quickly for smooth progress.
There can be a bit of driveline shunt between reverse and forward as the 4x4 system loosens up a bit and rear discs have been known to drag when mucky with dirt and brake dust, just like the 100hp's do.
The 4x4 ability is great even on the standard mud/snow tyres, mine regularly pulls me out of muddy fields and down farm tracks while the likes of X5's and XC90's just dig in the soft ground and beach without touching the ELD button.
I reckon it's off road grip is better than the old Disco I had.
The only drawback of the normal 4x4 is the front bumper lip/splitter can catch on rutted tracks, mine's took some abuse, but it's quite flexible and hasn't yet broken. Fiat seem to have sorted this on the Cross version with different bumpers.
On the road it has a little bit more corner roll, but it's hardly noticeable at normal speeds.
Drive it back to back with the 1.2's and you can sense when the rear axle starts to kick in and power up when provoked. On a wet roundabout you can sense the back end sorting it's self out and driving you around, it feels planted and right without being too noticeable or intrusive.
Hammer it around like a loony and the body does swing and sway a bit on corners, it's not scary but you can easily sense the 4x4 and stability control sorting things out.
I tried this on a snowy (private) road last winter and the way in clung on in there totally amazed me, my trailer over took me twice!
All in all I love mine, but too much city commuting does pain me because of the low first (but I do live in central london) and all the gear changing, but you can live with it if you can modify your driving style a little.