During Covid the "ready2fly" checkin was often more empty than the Sky Priority, so I would tend to just use it.

Except this one time in BCN were the guy checked my ticket and rudely told me to go in the SP line, where there were twice the ppl waiting 😩

In smaller airport often the standard lanes go faster because they only have 1 SP checkin so all you need is for one guy in front of you to have issues and you're good for a good 15mns wait.

Wish they used every single desk as a multi-purpose ones, or at least 2 or 3, because the solo SP checkin desk just doesn't work well.