Handling
The HUMMER has considerably bigger tires than the Land Rover. Remember that wider tires might look and feel better, while smaller tires can provide better handling in deep snow.
With its tighter turning circle, the Land Rover LR3 is doubtless sprier than the H2, something to consider if you do a lot of city driving; on the other hand, keep in mind that a vehicle with a tight turning circle may feel a bit twitchy on the highway.
Drivetrain
The HUMMER H2's engine is considerably larger than the Land Rover's. Remember that bigger engines may use more gas than smaller ones.
Torque equals pickup, and the HUMMER H2 will have picked up and gone by the time the Land Rover LR3 finally gets moving.
Utility
There's no clear winner between the Land Rover and the HUMMER H2 regarding transporting cargo.
Drivers with frequent child-duty might favor the Land Rover over the HUMMER H2.
The LR3 outpulls the H2 by a big margin.
Comfort
While the front cabin in the H2 offers a bit more head room than the Land Rover LR3, there honestly isn't much of a difference.
The Land Rover LR3 is not particularly more spacious for your passengers than the HUMMER.
Dimensions
Your wallet will hurt more every time you fill up the HUMMER H2 than the Land Rover because of its more capacious tank.
The HUMMER H2 rides lower than the Land Rover LR3, which is a good thing for its center of gravity and ease of access.
The HUMMER H2 and the Land Rover LR3 compete for the same parking spaces.
The H2's longer wheelbase will likely result in a smoother, more stable ride; on the other hand, the Land Rover may give a nimbler feel in daily traffic.
Cost
The destination charge is a standard charge for transporting the vehicle from its point of origin to the dealer. The Land Rover is substantially cheaper to get to the dealership than the HUMMER H2.
The Land Rover LR3 is significantly less costly than the HUMMER H2 in terms of MSRP.
In terms of out-the-door cost, the HUMMER H2 costs approximately as much as the Land Rover LR3 (though the Land Rover LR3 is a little cheaper).
Overview
The HUMMER H2 and the Land Rover LR3 have the same basic warranty.
Other
The LR3 emits fewer smog-forming pollutants per 15,000 miles than the HUMMER.