So I'm upgrading my saddle finally...is there a way I can make sure I get the same position back for the slide adjustment? are the measurement marks universal?

No and no. I would compare the lengths of the two saddles. If they sre the same, put the nose of the new saddle just ehere the old saddle was. Then make corrections based on how you sit on it. You can measure your knee position relative to the pedal spindle and adjust the new saddle to give you the same. Or just by comfort. If the new saddle is longer or shorter than the old one, adjust the starting point of the nose by half the difference in front or behind the old saddle position. . Again follow up with fine tuning.

Good luck

i generally measure the distance from the tops of my bars to the widest point on the saddle, seeing as thats where my ass likes to live but my saddles are all quite different in length/shape

was it you [MENTION=183557]rpenmanparker[/MENTION] that detailed measuring your bikes with the back tire against the wall? that seemed like a good method

Agree. Also for height, measure the height of each saddle, and adjust the saddle height by the amount of the difference. If the new saddle is taller, lower the saddle, etc. since different saddles compress more than others, you may need to make small adjustments after riding it.

Take a photo of the old setup from the side so you can approximate the tilt as well. Using a level is futile, since there aren't any flat areas on which to place one anyhow.

Took me at least a 100 miles over a week to finally dial my fit back in when I got a new saddle this year.