If my company offers an array of medical devices (and related software), do I trademark it as an 010 (based on it's flagship product) or do I trademark as an 044 (a medical service -- producing and designing devices)?
You can apply for trademarks in multiple categories, usually for an additional fee. If your business has goods or services sold in more than one category using the same mark, you can protect it in every category that applies.
With respect to each category, if a good or service in a category sold with a mark just like yours would harm your sales of goods and services that you currently provide, then it makes sense to seek a mark in that category. If your product line expands, you can also add categories later if someone else using the same mark or a confusingly similar one hasn't moved into that market in the meantime.
In the case of a medical manufacturing company, the cost of obtaining a trademark in an additional category after the first category (several thousand dollars or less), relative to the economic importance of the company's trademarks and the economic scale of your operations (which should be in the multiple millions of dollars), is so small that cost should be a non-issue. So, you should apply for a trademark in every category that you could plausibly and truthfully be said to do business in.
If you can't afford a few thousand dollars to perfect a trademark in a few additional categories, you should think twice about whether investing in trademark registration at all makes any sense, because enforcing a trademark in the face of potential infringement is far more expensive (tens of thousands of dollars to hundreds of thousands of dollars for each infringer who doesn't go away with a mere cease and desist letter and thousands of dollars a year monitoring the market for infringement) and if you fail to enforce your trademark in the face of clear evidence of infringement, you risk your trademark losing its validity entirely.