2010 Jamis Parker, 2005 Jamis Komodo, 1998 Jamis Komodo, 198? Raleigh Pointe, 1978 Schwinn Super Le Tour 12.2
It is a good beginner trail bike.
My best friend has been riding his off and on for a couple years now. He has bent his wheels and his big ring. He doesn't jump and he weighs 130#. I wouldn't expect it to hold up to very much jumping unless your definition of jumping is something like 1 foot off the ground.
It was made to either give you a solid platform for "occasional" trail riding or to wet your whistle for a future trade in.
As far as upgrades go...you could upgrade every part on that bike, but it's not worth it. Just replace parts as they break and enjoy the value that you got.