I virtualize Debian and play around with it, but the advantages of Trisquel
for me are:
It's easier. I have a limited amount of time to spend with computers and a
lot of things I want to learn. The legwork of deblobbing the kernel and
cleaning the non-free software has already been done and is being offered to
me as a gift. At this stage of my life, it frees me up to read my kid another
story or figure out how to get Alpine to check multiple email accounts.
It makes my choice more visible. Trisquel is pretty. People ask about it when
I take my laptop to a public hotspot or when they visit my home and see my
desktop. I may talk too much and they may be glad when I shut up, but at
least I am increasing their awareness in a way I couldn't if my computer just
looked like Debian and I brought up software freedom in a context that made
them feel i was judging their own choices or just randomly.
These would not be good reasons for not using Debian if I knew and loved it,
of course, and if anything happened for me to lose access to Trisquel, I
wouldn't spend much time feeling sorry for myself before rolling up my
sleeves and doing whatever I needed to do to continue to run free software.