Honestly, between the two (as owner of 2024 IG and 2026 550) I am not yet in a position to compare them in an off-road perspective.
Until the GX has at least 25,000 clicks on the ODO, I doubt I will off-road it as it will be my DD. I plan additional upgrades on it including skids as soon as BudBuilt completes the manufacturing process on them. The GX is still under 2500 miles, I have lifted it and installed some other off road gadgetry, White Knuckle Sliders, lights, roof rack, etc.
The IG I have NOT lifted, but have added full underbody metal cloak skids, White Knuckle Sliders and some scene lights. So, as a basically stock vehicle, I have taken it off-road and was quite impressed with its off-the-shelf capabilities. Does it need more clearance? Yes, absolutely! But with the underbody protection in place, it slid over all the rocks and had no issues as the diff-locks make it pretty unstoppable as it comes off the show room floor. I am a little too worried about lifting it as I would like to get some value from the warranty if I ever have an issue with the drive shaft.
I full well expect to utilize the IG as my off-road trail vehicle, and will install my HAM radio in it and possibly add a drawer/fridge system in the cargo area in the future.
Overall, I am not concerned with either vehicle. If I had to lean towards a concern, and I would only call it that, a concern, it would be the longevity of the IG brand continuing into the future for 5-10 years. I also strongly believe that the IG will be the most sought after off-road vehicle in the future once the used car market and aftermarket solutions become more robust for all issues.