I clearly remember the official declaration that Trello would be free forever. Though I do accept that charges could be asked for new features, extensions, etc., but Trello as it was during that official statement should remain free as officially guaranteed - including teams.
Now you are breaking Trello's solemn promise by demanding fees for features that were already there when the promise was made.
I have considered upgrading in order to have more power-ups, but since I would have to pay for the power-ups and pay for the privilege to be allowed to have more power-ups, I feel I would be paying twice for the power-ups, paying double. It is like paying an entrance fee to an amusement park and still have to pay for each ride. Therefore I have not upgraded.
I have over the course of years integrated Trello in my life and businesses, setting up extensive GTD-systems for myself and several "teams" in order to organize my businesses. Not only have I introduced Trello to hundreds of new users (making Trello boards for all new students of two educational institutions) - but you could say I have fully committed and surrendered to Trello. Now I would have to dismantle my entire organisation in order to reduce the number of boards per team.
Since Atlassian has purchased Trello it seems that the original Trello-spirit has been lost.
P.S. Please don't misunderstand me, I do appreciate Trello, as a matter of fact I love Trello! I am not entitled, ungrateful, unreasonable and such.
I think a more savvy approach would be to reward long-time users a multi-year discount or other discounted structure that helps retain them as users. It really just seems like Atlassian bought Trello, and now the corporate machine is simply going thru Atlassian properties and saying, "Oh wait, this is free? Let's introduce some kind of pricing to generate at least some income."
The free model wasn't entirely thought out by the architects of many different sites/platforms. It was easy to offer it in the beginning because 1) they probably had "enough" start up money and 2) there really isn't a better way to build a following and grow your user base.
That said, when my free platforms move to a paid model, first I have to decide if it is really worth it to start paying. In your case it sounds like you've gone all in on Trello so your answer is probably YES.
So if I have to start paying, I just try to think about the total term of the service. I might have used it for free for many eight years, but now have to pay $100/year. I conceptualize it by considering my costs to be spread out over that time, even if I am now paying $100/year. Kind of like buy now but first payment is due later with no interest (increases).
At least for now it seems like Trello has enough inherent flexibility so that one can work around pretty much any programming limitation or in this case a pricing/product change, as noted in Iain's post.
Fun times ahead. . .