[Mr70]

I would guess you are talking about the year 1969 of course with both fully documented.
With 400 L-89's made, to 224 COPO's made (Non-Yenko).Give me the L-89 because it is in Super Sport dressing as opposed to plain Jane Malibu dressing.
I like the trim and options better on a Super Sport model.They just look better.
Now if the L-89 was in a 1970 Super Sport Chevelle (18 made),then I jump over 10 COPO's to get to that car as well! I am biased to the 70 here.
Don't get me wrong,I wouldn't throw a COPO away,but if I had to choose between these two,that is what I would pick.
As stated before,rarity does NOT determine desirability.