The media debate about whether the bombs were "sophisticated"
This thing has been going back and forth for a day now, with media types tea-leaf reading other people's characterizations.
The hang up seems to be that nobody knows exactly what "sophisticated" means in this context, but what should be apparent is that these were very, very clever bombs.
Black powder is not sophisticated versus, say, C-4 or other modern plastic explosive. But a bomb-maker using C-4 doesn't manufacture the C-4. The bomb-maker is making a machine to make some explosive do something.
And using a pressure cooker from Walmart is, whatever its "sophistication," not a failure of the bomb-maker's craft. It works, with horrible results.
Why reinvent the wheel? If you can buy a suitable casing ready-made then that is smart.
We have two directional (which is sophisticated) shrapnel bombs with electronic (sophisticated) timing/firing mechanisms, and both went off within a few seconds of when they were supposed to, and did horrible damage,
So the bomb-maker very much knew what he was doing.
We also have elements that are crude-but-effective. (Black powder, store bought pressure cookers)
The bomber was very good at being a murderous terrorist bomber, but was very do-it-yourself and not rich. The bombs were inexpensive.
But anything that was fancier or more expensive would be more traceable after the fact and likelier to attract attention before the fact. Is avoiding detection sophisticated?
This was not a typical amateur bomber because a typical amateur bomber makes bombs that do not explode.
As to the sophistication of the device, when used by experts that seems to be a term-of-art that does not necessarily speak to the capability of the bomber himself.