I have 3 metal colemans (two stainless and a green one), plus a bunch of regular plastic coolers. The metal is definitely more durable, and I can get about 3-4 days of cold out of it, assuming I'm not using it for beer (lots of open/close).
I think maybe even more important than the type of cooler you get is your usage. If you have a family and stay out for many days away from ice refill, you might be better spending your $$ on more cheaper coolers than one really nice one...as has been mentioned, that way you can have one cooler for drinks, one for food, and one for frozen.
I have a fridge, but that's recent. Before that I went with the 3 cooler approach and could go 5-7 days in very hot temps (90-100 in Washington) with frozen food using a dedicated dry ice freezer cooler + drinks cooler + cold food.
What I'd do is keep one cooler full of drinks and ice. All the food in a separate cooler and frozen food at the bottom of the 3rd cooler + drinks at the top (where they wouldn't freeze from the dry ice). Once the beverage cooler was about 1/2 full, I'd do a mass move/refresh from the freezer cooler to the beverage cooler. That way I'd only be opening the freezer cooler a few times/day, but the beverage cooler was opened a lot...the cold drinks would basically act as the ice once the main ice would melt (it would last 2-3 days)...and remember a 50 degree drink on a 90 degree day feels a lot colder
Honestly, it was a lot of work, but it worked great. I picked up my stainless colemans on discount at $60 each (yes, great deal), so I had the coolers, so wasn't too expensive.
Now, I have a fridge, it keeps my drinks cold, I still have a freezer cooler, and my battery lasts 4-5 days w/o charging and I spend more time enjoying camping than worrying about moving crap between coolers
