I don't think it's a terrible use.

I've gotten up to 35% bonus before, so feel like the 25 is a bit low, but still not bad.

I fly almost exclusively TATL and I am usually very flexible, so I have had plenty of luck using my miles at low rates and am generally satisfied with the ability to spend miles. Could it be better? of course. It all really depends on what works for you.

But I will definitely +1 what fti said - miles for upgrades are not really a great way to use them. I just look for BE award flights - still a bargain at 100k.
(or 80k Amex miles with this bonus).