For a laptop with >15 Watt peak consumption, a fan based design is easier to get working on the first attempt: maybe the fan will rotate faster than strictly necessary, but it will work.
On the other end, it generally takes a couple of iterations to get a fan-less design right, because you can't simply slap an oversized heatsink into a mobile device.
I have two issue with dataflow programming languages:
1) They generally do not support batch processing. In the past, when I needed batch rename variables in a dataflow, my solution was to export the flow into an XML, do the batch rename in a text editor, and import the XML back.
2) They generally do not support macros (operators, which would generate new operators). As a workaround, I was using Python scripts to generate the XMLs...
On the other end, it generally takes a couple of iterations to get a fan-less design right, because you can't simply slap an oversized heatsink into a mobile device.