Take the saved $$ and use towards mods and be happy w/ what you bought....
I bought my Dolomite for $280 shipped and added apes then used conduit bender to lay back my seat post. I also relocated the twist shifter to the frame and ran the brake lines thru the bars(to hid most of the cable)...
I really like the look of the narrower tires stretched onto the 4" rims (low profile) but the stock balloon look of the 4" Dolomite tires get such a reaction (OMG those are huge) from people it makes it hard to pull the trigger on new tires....
Don't get me wrong about a free-$20 dumpster bike...it has it's place...
Mongoose is still a VERY reputable brand....They have bikes for ALL ages and price ranges...They make one of the best DH bikes on the market
http://www.mongoose.com/usa/bikes/mtb
out
That "Mtn Bike" is a mtn bike by name only...for riding it on flat trails only....I personally wouldn't actually ride it on any hills b/c the weak components....It's basically a coushy "around town rider"....
Changing the Stem won't save you much weight....I would only change if you wanted a short stem to adjust riding position. The stock stem takes 31.8mm bars....Putting on some wide graphite bars would help w/ handling and weight...I'm using the stock seat post so I don't know the size off the top...
I like the hyrdo formed frame and tire pattern better then the Dolomite...
If someone ....... that the components suck they shouldn't buy an inexpensive bike. The better components make the price go up....seems like a lot of people around here ..... and rag on the bike rather then take it for...
As a Mtn Bike I can see the deficiencies in the Dolomite BUT I converted mine to a cruiser (added apes/bmx style stem/laid back seat post/made twist shift into suicide shifter and routed brake cables thru the bars(done after pic)) for less the $300 total cost.
I would take the OG forks. cut them at the stem and rotate them a little to add a couple inches to the wheel base but keeping the look of the rigid front end...