Depends on how you look at it. Quality on hubpages is a lot higher on how to articles because people are usually writing them from a personal point of view and not for the money. E-how has dropped in quality over the past few months as a lot of the how to's I have seen there are just popped together in order to get them up. Most of them are not helpful and sometimes don't even go into real detail about the how to.
With hubpages most of the how to's you find have great detail into them and even explain the negatives or what could happen if not done the proper way. As for the volume you have to get people to write the how to and produce a lot of them in order to surpass E-how but in the future the more people who put up how to's hubpages might surpass them.