I don't know about "no point to making comparisons", but they are definitely different animals.
When I worked at Samsung, flash & LSI were like 2 different companies. Lots of reuse at the systems engineering level though. At a certain point of abstraction you can't tell what is on the wafer anymore so you might as well track it in the same database.
Completely different animals. I know that when TSMC has looked at acquiring used fabs before and in at least one case because the fab was DRAM it was more costly and time consuming to convert it to Logic fab than just building a whole new fab.
When I worked at Samsung, flash & LSI were like 2 different companies. Lots of reuse at the systems engineering level though. At a certain point of abstraction you can't tell what is on the wafer anymore so you might as well track it in the same database.