Larry Baxter & Vasken Bakalian -
The reason I'd used 0.49 is that it prevents an issue of rounding up/down on a whole number, but I believe it still offers the same level of accuracy in rounding any other numbers. You can see with the first result, [Number]+0.5 is causing 1 to round up to 2. That being said, ROUNDDOWN() and ROUNDUP() are both on our list for future functions!

As for the original formula I'm sure there can be optimizations made to simplify the syntax, but here's something I've put together:

CONCAT(\nROUND(DATEDIFF([Date Range].[Date Range Start], [Date Range].[Date Range End], \"hours\")/24-0.49, 0), \" d  \",\nROUND(DATEDIFF([Date Range].[Date Range Start], [Date Range].[Date Range End], \"hours\") - ROUND(DATEDIFF([Date Range].[Date Range Start], [Date Range].[Date Range End], \"hours\")/24-0.49, 0)*24-0.49, 0), \" hr  \",\nROUND(DATEDIFF([Date Range].[Date Range Start], [Date Range].[Date Range End], \"hours\")*60 - ROUND(DATEDIFF([Date Range].[Date Range Start], [Date Range].[Date Range End], \"hours\")-0.49, 0)*60, 0), \" min\")

I haven't done extensive testing on it, but it looks to produce the expected results.

Formula to calculate duration from Date Range field?