I don't think the performance is too much of an impact... the original goal with the Ultra shader was to replace the other ones, but if text just needs to render simply, I may as well include a more basic shader to use/use for editing.
There's *one* small downside, which I'm currently fixing, but it's such a rare use-case that no one has reported it for a year until I noticed it myself last week. Already got workarounds for it btw, just deciding on the best one to implement.
And awesome, make sure to set up materials with the Text Data editor! But if you've already figured out quads you're probably familiar with this system already.