While I agree that Ad Hoc is superior to Analysis Workspace when it comes to speed and certain functionality, you'll need to plan to not be able to use it anymore. It's EOL is March 2021. Some Ad Hoc functionality, such as being able to export large numbers of rows, has recently been added to Analysis Workspace.
Ya, but the current biggest challenge is there will be no "Site Analysis" anymore.
Omniture, won from a website analysis tool, but now, it's more moving to a digital marketing data reporting tool. - I don't doubt it, but the website analysis is a vital reason we use it, it has been providing very helpful resources for Website redesign.
Site Analysis, can show the "from-to" among touchpoints clearly, with customizable dimensions and metrics in a 3D view way, this is very helpful we over-view a customer journey compare to designed content structure.
Hopefully this function will be back or be added into web version analytics.