It's indeed the latter. Psychologically harder for me than a $20/mo sub but still a better value for the money. I'm finding myself spending closer to $40-$60 a month w/ openrouter without a forced token break.
Edit: it looks like it's 75% off right now which is really an incredible deal for such a high caliber frontier model.
Neat, dumb question - are the tokens you prepay for good forever, or do they expire? And do they provide any assurances or SLA's about speed? (i.e. that in a year they won't decide to dole out response tokens to you at a snail's pace)