WOW, there is some serious misinformation and brand-fueled ignorance spewed in this thread.
Here are the facts:
A vehicle is evaluated on several criteria, not just one. This is particularly true when considering an overland vehicle. I have a G-Wagen and have owned, wheeled, raced many Toyotas, including the 80 and 70 series.
Capability: Tie
To say that a G-Wagen is more capable on the trail than an 80 or 70 series Land Cruiser is absolutely false. An 80 and a G-Wagen is essentially the same, both in design and in use. The G has a slight advantage in sand with the ability to perform a rolling (5mph) hi to low range gear change, but other than that, they will be exactly the same. The 80 series is more stable, the G has faster acting lockers. The G has a better departure angle, the 80 has better differential clearance - splitting hairs. The Jeep Unlimited will run circles around both.
Durability: G-Wagen- Barely
The G-Klass is build to a higher degree of durability, with larger axles, heavier frame, larger components overall for the GVWR. This comes at a cost in purchase price, curb weight and poor fuel economy (yes, there is a truck that gets WORSE fuel economy than the 80 series).
Reliability: Land Cruiser
Sure, the G-Klass is reliable, but even the most basic understanding of automotive manufacturing proves that it is impossible for the G-Wagen to be more reliable than the 70 series. This is by nature of the assembly process, the G being built in small volumes, by hand. No matter how good the workers are, there are variables impossible to control. Though reliable, the Gs failure modes will be less predictable. Toyotas are build under the TMS, the best in the world. Reliability issues will always be more predictable with Toyota. Based on the service history of my 463, the G-Wagen does have more issues than a comparable 70 series.
But, for the sake of argument, lets assume that a 70 series and G-Wagen 461 are exactly the same reliability. Then why would the Toyota win? Serviceability! Go to any developing country in the world, and there will be 70 series trucks running around and a dealer network and mechanics to service them. Fact.
There is a difference between durability and reliability. Durability is the designed ratings and construction of the individual components. Reliability is the workmanship, the assembly, the long-term service of the various systems without failure.
People are passionate about their trucks, and they want to "prove" that their purchase decision, or brand is the best. The fact is that no one truck is perfect. The Jeep is more capable on the trail than the G or TLC, yet the G is more durable than either and the TLC is more reliable and serviceable than them all. Pick your flavor.
The real advantage of the G-Wagen from my perspective is the fit-finish, durability, balance of road/trail performance and that it is so unique. The G-Wagen gets us the classic design and uniqueness of the Defender, but the build quality of a Toyota. For me, that is worth the price of admission