I'm not expert but I first plan to buy allion then moved onto axio.It is basically because of changing requirements.First identify your /family requirements what do you expect. Then go for the car.
I did a 1 month study about allion and axio before we buy axio.What I can say is allion is more into comport where axio is not.again that change in model(year),grade (x,xltd,g in axio) and (x,gpackage ,ggrade in allion).
NZT 240 is 7 years old car where axio 2007 is 4 years old car now. so if you plan to use for a while my advice is go for axio which is newest.
Another thing is you can buy axio unregistered one so if you are leasing there is a chance becouse of VAT reduction but if you go for registered allion you have to pay 12.5 vat extra.