It greatly depends on the hardware and what bootloader it runs. If it does not have an SD card slot or if it has bootloader 1.****, I would not touch it with a ten feet pole.
If it has an SD card slot and bootloader 4.**** or 5.****, it definitely has possibilities.
Having said that, I would pick a GO model any time. It has 400 MHz and 64 MB compared to 266 MHz and 32 MB of the ONE and XL models plus it can use internal and SD memory at the same time.
Everythin with this model is intenal ,with no option for an external sd card.
Ok,so updating the navcore is not really an option......so i'm left with maps , am i going to have issues updating just the maps?
Eventually, yes. The fixed memory in an XL is limited to 1 or 2 GB and maps are growing all the time. Right now the Europe map comes with an option to load different parts into memory because it is over 2 GB in size. Goes without saying that this feature only works with original maps.