I have no arches and I am training for the Susan G. Komen Breast Cancer 3 Day so I needed shoes with motion control, I previously had 2 pairs of Addiction 8's and since the Addicition 10's came out the price on the 9's dropped so I got a pair.  I am very happy with the Addiction 9's, they are quickly getting broken in. These are technically running shoes but they are just as valuable for walking too!

I tried for years to get comfortable walking and working out in "cross-trainers" until I realized in 2008, when I did my first 3-Day, that motion control shoes are an essential for all the training I was doing.  If you have no arches and you are not using "motion control" shoes spend the extra money on these shoes, your ankles and joints will thank you in the years to come.  Good Luck!