I have an assortment of 270 awnings ranging from 400 bucks to about 1500, the only one that is completely self-supporting that I have owned is the Alu-Cab Shadow Awn and it's also the most expensive (1500.00) and the heaviest. The others that I have starting from cheapest to more expensive are the
Guana Equipment Morpho 270 Degree Awning ($400.00) - awesome for the price, decently made, and off the shelf parts, makes using common tools and parts from Home Depot very easy. Set up by one person is an effort of frustration and no self-support aspects at all. It gets the job done, but nothing "easy" about it.
Rhino Rack Batwing ($800.00) - probably the best known 270 awning, at double the price of the Morpho, you can tell there is more engineering and better materials, replacement parts are easily available but have to be gotten through Rhino or re-sellers. Problems, it does not use industry standard (sizing) awning mounting, is larger packed up than most awnings, and while it's easier to set up with one person than the Morpho, it takes longer to set up than the Morpho. Mine got ruined the first time I used it on a trip to Montana, I had it staked and guide roped down as instructed and winds were strong enough to flip my rtt over on itself, two of the poles bent 90 degrees and I had to cut the awning to get them out so I could pack it up.
Overland Vehicle Systems Nomadic Awning 270 ($900.00) - Here is where I found the best compromise, it's self supporting "only" for set up/breakdown, but this makes it really easy to set up and breake down, it's also has a bar that goes forward so you get more coverage than any of the other awnings I own. Quality is on par with the Rhino Batwing, but there is no, to little plastic used, so it feels more robust, but the awning material and robustness isn't as nice as the Alu-Cab. I would of gotten another Alu-Cab, but it didn't cover areas I needed for my trailer that the Nomadic does. The Alu-Cab is still easier/faster to open, but this awning breaks the difference between the Batwing and the Alu-Cab. As I've said, this is a great compromise when price is a factor. The one thing I would want changed is a coating on the awning material to reflect the sun (which is something the Alu-Cab has). This awning also came with the most robust mounts that you should be able to mount it to anything. OVS just released a smaller version called the Nomadic LT, right now priced at 599
Alu-cab Shadow Awn ($1500.00) + Beautifully made, robust materials, great engineering and it's actually cooler underneath the awning when the sun is beating down. It is relatively small compared to other 270 awnings, but it covers enough area for most people. The mounts are specific and have to be purchased separately adding to the cost and the complexity to mounting. It's relatively heavy. Set up and breakdown is a dream and I never hesitate opening it even for a short time, which doesn't happen with any of the others I own. You do feel you get what you pay for, but it might be more than most folks need. I did have the bars break and bend by a huge gust of wind down at the beach, the folks that were using it didn't use the pole included or guide rope it down, which alu-cab says you should do for potential strong winds, however OK4wd was able to sell me new bars at a very reasonable price.