I owned a 2014 G550, 2016 G550, and 2017 G63. I currently own a 2020 LC HE.
The G63 handled FAR better on the highway than the G550’s did due to the different suspension tuning and both versions of the G have more power than the LC, but again the G63 has a LOT more power. The G63 was quite frankly a blast to drive. The big downsides to the G’s are Mercedes vs Toyota reliability and MUCH higher maintenance costs - parts are $$$$.
The LC is definitely the option that will get less attention, but I didn't really care about that either way. As far as that goes, buy what you want and don’t worry about what people think, unless it's your spouse.
As far as space goes, the rear seats in the LC are roomier, but at just over 6 feet tall and a big build, i was perfectly comfortable riding in the rear of the G's on long trips when we split up the driving. Cargo space is actually fairly similar, but shaped differently. For reference on the cargo space, I had built a cargo shelf for behind the 2nd row on the G and it almost fits like a glove behind the 2nd row seats of the LC.
I looked at the new 2019+ G when it first came out and really didn’t like what they did with it as there’s less cargo space, it has way more bling inside, the MSRP went much higher, and it just lost a lot of what made it special IMHO. I was pleased to see that they kept the exterior styling very similar though.
All that said, I’m trading the LC in for a 2024 Highlander Platinum on Friday. I just don‘t need all the capabilities the LC has and have to go into the office 3 days a week now, so I really need something that gets better mileage. The Highlander is a reasonable compromise that gets me better mileage but can still haul stuff when I need to. I’m getting just about what I paid for the LC 3.5 years ago on the trade and leaving with a fully loaded Highlander and a big bag of cash, so I got to enjoy the LC for 3.5 years for pretty much nothing. There aren't many vehicles out there that hold their value anywhere close to that well.
Great comparison but you lost me at the last paragraph—trading in for a Highlander? I commend your financial discipline, but I hope you don’t regret that decision!