At the end of the day you have to go through all the videos and footage and it's what you're happy with mate - if you just do daytime driving then a G1WH would be fine - for night time the G90 is definitely better. If you want GPS then you have to pay more again.
A G1WH is better than what you have now, and a G90 is better again.
If you watch one of Niko's videos here:
Basically you can see that the LS300W is better at night than the G1W - well the G90 is better again than the LS300W. Personally I'm a fan of detail and would love a dashcam that retrieves brilliant detail at night when you pause the frame.
The common view seems to be that all the A7 devices like this G90 and the Mini0803 are better at night - whether that's worth paying the extra money for is all down to your budget.
The G90 is also better at night than the GS6000 A7 device I had when WDR was turned off - with WDR turned on they were just a mess at night time.
My next cameras are going to be either an OV4689 with A7LA70d like the Marcus 4 or one of the new DOD LS460W type with the new Sony sensor as they have a lot of potential but are at least twice the price of the G90. I'm hoping a new Panorama device will come out with the new Sony sensor so I can get my hands on one of those!