Re: Redington Drift or Cortland Retro???
Both reels will fit the Struble reel seat on the Sage ZXL.
I can't remember capacities, and I am too lazy this morning to look them up. They should be similar. Redington uses a mid-arbor design with a wider spool for its capacity. Cortland goes old school with a standard arbor design with a narrow spool for its capacity.
As for drag systems, they are simple click systems. One pawl up and one pawl down will determine direction. If I had to lean towards one for better quality of build on the drag, I'd lean towards the Cortland. It uses a beefier spring.
What it may come down to is which reel is better looking on your rod?