I barely remember this series being on Jetix when I was a young lad. Lately though I've gone through a Nostalgic phase (probably brought on by the boring world of the 2020s) and I decided to rewatch this. I basically went in blind considering I barely remembered a thing from it. And was very pleasantly surprised! The continuity from the original series, comedic writing and classic noughties animation holds up very well! There are a few things I thought could have been done better, the soundtrack when compared to the original series is very poor. And the opening theme song especially is just the "George of the Jungle" theme but with the word "Gadget" instead.
Overall, I would consider this a solid successor to the original series. Maurice LeMarche as Gadget was a great casting choice, and the voice actor of Dr. Claw does a good job as well. I'd definitely recommend it! I'll definitely show it to my real life niece when she grows up a bit and stops being a baby. (Literally)