I've got a '07 sputnik and it's great...the masi is a nicer looking bike IMHO (it was my first choice but they were sold out for the season in my size at my time of purchase) but the sputnik is better made with generally equal or better components than the masi...
The only real downsides to the jamis are: an absolutely SH1TE saddle, a low bottom bracket coupled with longish crankarms, and a 48x15 gear that punishes on the climbs...
I had initially planned on ebaying the easton fork and replacing it with something lugged and steel but, as it turned out, I am quite enjoying the muted ride feel coupled with the stiffness...I wish the Easton logos weren't so loud though...if you're buying the '08 model, that won't be an issue since jamis is now using a house-branded all carbon fork...
I've replaced the aforementioned sh1te saddle with an old silver riveted san marco regal titanio, I've swapped out the 15t cog for a surly 18t, and I try to ride in as much dirt and mud as possible to cover up the Easton logos on the fork...
me=happy