Chris Webb lays out an argument:
For as long as I’ve been using Power BI – which has been from the beginning – the advice about which storage mode to choose has been the same: use Import mode unless you have a really, really good reason to use DirectQuery mode and even then you’re probably wrong and should use Import mode. Import mode was always a lot faster and a lot easier to tune. Marco’s advice in this LinkedIn post from last year pretty much summed up my attitude and that of every other Power BI expert out there:
Click through for Chris’s argument. As a side note, I saw Conor Cunningham present a session this past weekend at SQL Saturday Austin on the GPU acceleration that Chris mentions in the Fabric Data Warehouse, and under certain circumstances (think “classic Kimball model”), it results in a 2-10x performance improvement, with the expectation somewhere around 3-5x. In other words, a query that takes 50 seconds to run and makes sense to run on GPU drops down to about 10 seconds with no development effort. For well-designed semantic models, this might be a significant factor that pushes the trade-off rubric in the direction of DirectQuery versus Import or DirectLake.