Its not new (providing a fake "library" that generates known responses to enable one to test code at a higher level was something I was taught over 20 years ago) and its therefore not a fad - and it certainly shouldn't "double" the developer's workload - although it does, like all testing, add to the up front effort (which should be more than recovered later on). Is testing a pain? Yes...

I always use details view, I have almost always used details view - not least because it enables one to rapidly change the sort order. Don't use list because its neither fish nor fowl...