I have a 2007 Marin Rock Springs which is very similar with fixed 140mm rear suspension and I think the Alpine link as standard.
I purchased it second hand for a trip to the Alps and it has now done 4 weeks in the Alps and a couple of weeks in Spain.
I have no idea how it compares to a modern all mountain/trail/enduro bike, but it feels much slacker than my 2011 Anthem X and it doesn’t seem to stop me riding the same trails, at about the same speed, as my mates on our trips away and they have more expensive, more modern bikes…and those trips are awesome and make me smile and laugh a lot, which makes it a great bike!
All of the above said, only the frame and rear shock are original. Replacing the QR rear with a through axle and changing the wheels for some cheap All Mountain wheels made a difference to the rear flex, 150mm forks, wider bars, shorter stem and a dropper post have all improved things each year.
I keep thinking about replacing it but struggle with spending a few grand on a bike that gets ridden for a couple of weeks a year…maybe for next years trip!