I have the Gen 3 and had the Gen 2 just before it (got it removed and changed over). The difference is huge. The cable might be slightly smaller, but it's also much lighter and easier to use. I also had issue with the Gen 2, where at times it would short out the fuse box when I had a lot going on in house (dryer, oven etc). I spoke the the electrician that installed it and he mention the Gen 2 doesn't have any DC protection which would likely be the cause of the shortages, he also mentioned that he has had many clients that he has been recommending to not use Tesla Wall Connectors because of this reason. When he installed the v3 he said that it was a big game changer.
Plus the the unit itself now connects to wifi, which means it gets updates and let me control it from wifi, which is pretty neat.