Try some more navcores before you decide to give up on it. For eg. try mark's other navcores, such as 9.485 SE in post #112:
You can update your device to the latest official navcore in TomTom Home and see if that suits your needs. More info on how to do that in the Tutorials section.
If you finally decide to return the XL2 model, try to find a used GO model x20 or x30, such as GO 520, 720, 920, 530, 730, 930. Or any of the x40 and x50 GO models such as the GO 750 are all still crackable. They all have a card slot, so you can use almost any navcore and any maps you want.