Asics Kayanos are the ultimate best running shoes out there that are easy on your budget and on your feet. They are lighter on your feet than a typical running shoe and offer a better support.
The Asics GT 2160 are one of the most popular and highly sold running shoes. They are extremely comfortable and have long durability. They make even the longest run seem short.
If you a running on a trail or trail-type surface, than yes, the asics trail running shoe would be ideal for a marathon. If the marathon is on a hard street surface, then I would research other shoes.
The following website offers reviews and comparisions with Asics running shoes: http://www.runningshoesguru.com/ This website also offers much more information about Asics and other running shoes.
I suggest you buy asics. They can be fairly inexpensive depending on the type and what store you get them at. They last a long time and are very well made.
Asics running shorts are available from ebay, sun & ski, Macys and various other stores. For price I would recommend shopping at sun and Ski with a price of $19.
If you are looking for Asics GT-2160 running shoes, there are a variety of sites that offer this specific shoe. They are available on Amazon, as well as other sites such as Sports Authority and OnlineShoes.
It's not just a running shoe, it's more of a comfort running shoe. Some even have Gel insoles like the ASICS GEL-Lyte33. They also have great design and appeal. I don't recall other brands having such great features.
Amazon sells Asics Womennibus along with many other running shoes and also check Zappos they have a lot of great running shoes that are usually less then the buyer is asking for.
To the best of my knowledge the advantage of the Asics Gel running shoe is that it has gel in the insoles for more comfort and support. These shoes are available at Kohl's, Zappos, Amazon and Ebay.
Asics are a good brand of running shoe, however, it all depends on what you are looking for in a shoe. You are best off trying them on before buying them.
To read reviews from other people who have used this running shoe you can go to www.runningshoesguru.com or check out runnersworld.com/shoeadvisor or also try www.amateurendurance.com/gears/view/Asics-gel-nimbus.
Asics Gel Kayano 14 has the largest heel pad ever used in the Asics running shoes. It has more support in the midfoot section which protects the feet from injury. It also has extra fit to the heel which increases stability.