I don't think it matters when you launch. If it's a mini-preview you might not want a big fanfare, but rather a small launch so that you can get users on board,

I don't think it matters when you launch. If it's a mini-preview you might not want a big fanfare, but rather a small launch so that you can get users on board, get feedback and continually improve until you reach a stage where you're ready to really pump up the PR machine.