I bought a cheapo chip on Ebay and had a look at it. Its just scaling of fuel. It has never been near a dyno.
The Squadra chip is on another level. As an example it has a modified software that changes how the cam phasing works. Standard Alfa it's only rev dependent, but in Stephan's chip it is also load depending, resulting in better low rev driveability.
Raising the rev limit is the easiest thing in chip tuning. Just change a two byte value in this case. It's not a indicator on how good the tuning is. My Squadra chip has the same rev limit as original. I'm not interested in overreving my engine, peak power is anyway passed before i hit the limit. But if you wan't a higher rev limit any serious tuner should be able to set it to whatever you want.
This is pretty much what I have read regarding the chips. Most people seem to suggest that of the non-custom mapped chips, that the Squadra chips are miles ahead of anyone else due to the facts that you mentioned (They offer a custom map option too).
I think the thing people also miss regarding tuning is that they seem obsessed with the bhp increase rather than the increase and changes in the torque curve which is probably the most noticeable benefit for day-to-day driving.
The Squadra chips give a peak increase of 14nM (ph1) and 11nM (ph2) respectively along with a peak power increase of 10bhp (ph1) and 7bhp (ph2) and when you look at the torque and power curves, the biggest benefit you will see will be from the added torque (especially in ph1 cars) as you're getting an extra ~15nM on a phase 1 between 2500-3000rpm which is regularly achieved unless you granny shift (extra 11nM 3500-4000rpm for ph2) and it going to give you a noticeable improvement to how the car pulls lower in the rev range.
Whereas the main power increases don't occur until right up in the rev range (>6k rpm) so its not of any great benefit unless you're thrashing it, and if its a daily driver, more than likely you're shifting well before 6k rpm.
Then add in the fact that Stephan has changed the idle and throttle response to create a much smoother running car, and to be honest, you're unlikely to get better performance increases for daily driving, for the same money. Otherwise you'd be changing internal hardware like cams, valves, pistons etc. and that is far, far more expensive than a Squadra chip.
Mind you, any decent custom tuner with a dyno should be able to give similar results to a Squadra chip and for the OP, as like me, you are based in Australia, I think going to a local tuner is the best option