2 cents
Glad you purused the rack thread.
I'm no expert, but IMHO exterior storage is one of the most subjective aspects of 4x4. The more thought you put into your needs and uses, the happier you'll be. I've been in the selection process for a couple of months now, and I still haven't made up my mind.
Height: Make sure that you're willing to live with the increase to vehicle height by both the rack and it's contents, especially bicycles. Consider the clearance of your garage, parking garages, branches on the trail, etc.
Weight: Every pound up there affects your vehicle's center of gravity.
Add up the weight of the items you intend to carry and compare the total with the rating for the carrier. Then add the weight of the carrier to the total and compare to the rating for your roof.
Especially if you've already got an ARB bumper, winch, lift kit, sliders, and front-to-back steel skid plates, add up 1) your current full-gas-tank vehicle weight (you can get this by taring at many trash dumps), 2) your intended carrier & contents weight, and 3) intended passenger weights, and compare the total to your vehicle's GVW rating.
Lights: If you're going to add lights, choose them first. Then the rack. Then figure out where the wiring will be routed.
Spare Tire: Spares are tall (See height), and heavy (See weight).
Noise: Wind noise at highway speeds can be significant, even unbearable over long trips (think high pitched, constant whistling).
Weather: Unless you get a closed carrier, or use closed containers in an open carrier, your stuff is going to get windblown, dirty, wet, etc. Tarps can help, but can flap (See Noise).
Options: Alternatives to open roof carriers/racks:
Hitch mounted carriers - Easy to remove. Don't affect height. Relatively lower center of gravity. Some fold out of the way when empty. Some have weight ratings that exceed those of your roof.
Trailers - More expensive. More weight and volume. Easy to remove. Harder to 4-wheel with one attached. Check out some of the camping trailers on this site.
No matter which option you choose, your gas mileage will suffer.
Good luck.