Sorry if this is meaningless to you but I find it interesting.
Ok so since I started walking I like everyone else have been through a variety of shoes.
I have used Hitec and Merril trail shoes.
New balance- a variety of cheaper trainers, some ok some poor - hurt my Plantar.
Then I discovered Asics Nimbus 10, my first pair of blue ones were great did 1300km and still felt ok.
At around 600km on the blue ones I bought some red ones, well these never felt great not quite like the blue ones, but I still got to around 1100km.
Again at around 400km I bought some Nimbus 11's which I wanted for Comrades, these have now done 600, feel better than the red but not as good as the blue.
The 11's feel bigger and heavier than the 10's, the new 12's are even bigger with a higher heel.
Walkers need a flatter shoe with lower heel.
I bought some Asics Hyperspeed 2 on special, well I found out what flat shoes can do for speed, they just feel so fast and at the price even if they last half the distance they are well priced. I hav edoen 2 21's in these and they are fast but I will need more support on longer walks.
I have just got some NB MR828 which is a lightweight trainer but I can still feel the cushioning , well at least on my first walk in them today. I bought them for every day up to 10km training. I do not want to kill my Nimbus too soon. I did notice that my Plantar got stretched today , same as my previous NB's.
I also got some Asics Sky Speed's which are similar to Nimbus, but with lower heel , straighter last ( is the shoe is straight and not curved) and has narrower heel and sole. Liz does not like the colours orange and yellow. I hope to use these for my 50k race. I am doing a 25k walk followed by a cycle of the route on Sat, the cycling should help me stretch my hamstrings. I will try out the sky speeds then.