For what is worth, I have owned the Do-Wins (older model from 2008 and newer 2010 models). On both pairs the rubber sole separated from the wood by the 4th workout. Also, a few of the guys purchased the new Do-Wins and all experienced the same thing. We happened to all by the gray ones. The first pair I bought I just stuck it out. I glued them several times but within a month they were falling apart. The second pair (2010 version) were returned immediately, because like you I felt they should be a little better built than that.
So far the Kanamas have held up well since January. No issues and they are extremely comfortable. I have feet in like Fred Flinstone, therefore, they fit wide feet.
I will probably try the Risto's next but one of the guys we train with has a pair (the white ones) and the wood is starting to separate, but I have to admit it looks as though they were left in water. It looks like how plywood separates if wet.
To be honest, don't waste too much time trying to decide....just get a pair and start training with them. Unless you have poor ankle mobility, the heel height won't really matter. Both the Do-Wins and Kanamas fit true to my dress shoe size.