All the designers at this firm just sit at desks all day and plug stuff into Rhino and work from 9am to 7pm. I've asked around and they say it's basically about 90% of what they do... 5% is working on models occasionally, and the other 5% is traveling to do some research.
Ouch. Most of what I do isn't CAD, even if a lot does occur at a desk. My work isn't monotonous at all most of the time. I do research onsites, lots of ideation sessions with the team to work through the product's problems, meet with clients and vendors, write reports, use products to understand and speak to ergo issues, sketch, make mockups, build CAD, work on GUIs sometimes, work with engineers on configurations, it varies quite a bit and really depends on what the project's goals are - often the project goal isn't even about delivering a finished product design. I know places like the OP describes do exist, but it would definitely crush my soul to work in them as I am far more interested in the totality of the product development problem solving process than in being a form master. I've always worked in smaller groups and found I like the constant mixing up of functions and project types - maybe that's what the OP needs also?