Just that...
I find in them anything I need, tone and definition-wise, and I just couldn't be happier with their quality!!!
I like to play around with different tunings, and thet offer a wide range of gauges. Also, the fact that a huge range of singles of any gauge are available to customize sets, is brilliant!!!
From time to time I try other brands, and many are OK, but is just I have found my feel and tone with D'Addario, and I'm always going back to using them.
It's a matter of taste, as always when sound is involved.
For me they're PERFECT, I love them!!!