Considering trying one of these saddles on my Tri bike. Anyone have time on both and comment on real world usage?

For someone who doesn't have great hip mobility and flexibility, so you all have a recommendation on one vs the other?

Is the stage basically impossible to sit up on? Or is still pretty comfortable?

I have some SI joint issues so need to stay a bit mobile/adaptable on the positioning when going longer than 30 min or so.