I wholeheartedly agree that raised beds with timber sides, create problems. Weeds seem to get established along and under them, and they provide refuges for slugs. My experience has shown me that any interface between path and growing area seems to create problems which are much underestimated by the majority of gardeners. The worse situation is where the boundary is grass because it needs regular maintenance,(which it never seems to get), provides hiding places for slugs and encroaches onto the growing area. It may not be a textbook idyllic garden but I have settled for 8ft beds with bare paths.
However; I now have one plot which is planned to be mainly fruit, I also have a quantity of old decking boards. I have grassed half of it, so that I can mow between apple trees and upto a linear row of raspberries, (these sucker for fun in my sandy soil). The other half is planted with blackberries, loganberries, strawberries, rhubarb etc and is going to be edged with boards which will be above the level of the surrounding grass. The aim will be to regularly mow upto the boards to prevent encroachment. Well thats the plan 
Cheers Pete