See, most running shoes have these horrible huge overbuilt heels that practically force you to land heel first...which is the worst way of running especially when combined with overstriding (stepping too far in front of the body) and by far the main cause of running injuries, because it basically creates a braking motion with each step, especially hard on your knees and lower back.  What most people find to be a far more efficient and enjoyable way of running is to strike with the midfoot and land directly underneath or slightly behind the body...something which is difficult and sometimes impossible to do if you have the misfortune of having bought one of these huge-heeled shoes (the Nike "Shox" series are probably the worst of the worst).  I suspect the reason that shoe companies like to put huge overbuilt heels on their shoes is because they know that most people will assume that "bigger is better" (kind of the SUV-buyer's mentality) and are also unaware of midfoot running as an alternative.

Well these 790s are one of those rare exceptions.  While not completely flat-heeled, it's noticeably lower in the heel than most shoes, which makes midfoot running much much easier.  The shoe is also nice and light and the outsole is fairly flexible: lightness in a shoe = more speed, flexibility = the muscles in your feet can stretch/strengthen themselves more fully and naturally with each step. There is a flexion plate which provides a nice bit of energy return too.

My only slight quibble is that the fit is a bit looser in the 790's forefoot than I would have liked.  This is dependent on the shape of each individual's foot, however.  One of the reason I love Brooks shoes is because they fit my feet like a glove, and a shoe salesclerk confirmed that Brooks are especially good for people with narrow-ish feet and low to medium arches, like me.  So if you have slightly wider feet, perhaps with slightly higher arches than mine, this shoe might fit YOU like a glove.

That said, I still use my 790s for short runs of 6-9 miles on grass or dirt, including tempo runs.  They're ok on asphalt or concrete if you are a highly efficient runner with a really soft stride, otherwise they can be a little rough.  I have used them for daylong hikes and they were extremely comfortable---the low heel and the lightness made them far superior to my usual hiking shoes.  I wouldn't recommend them for really difficult trails of course, but for casual easy trails they are wonderful.  They are also so attractive (I have the gray and black model) that I will use them for casual wear when they have worn out for running...took them on a long flight once, they were also very comfy.
I bought mine for about forty bucks online with shipping included; not sure if I'd pay full retail price for these.