What Teacher Lori said is interesting because I'm super young and ironically I never say "sick"; I would much rather say "cool" or "awesome", and there are definitely kids like me (below 25) that just don't like certain words/slang. Saying things like "sick" is just not the way I talk. So personal preference is something to consider.
I think there is a frequent usage of "sick" among younger generations (where it's used that way), but not that that "awesome" is dated or falling out of use, y'know? Is it less commonly used? ..Slightly, maybe. Is "sick" used in favor of "awesome"? Yeah but I'm sure you can find cases of the reverse, so yes and no. This would be a fun thing to look into.