Co-designed by GM with Isuzu initially, but they are (were) built stateside by GM at the Tonawanda Engine plant in NY, as stated above. They are no longer in production of course, with the end of the 1st gen 355 truck production in 2012 and introduction of the 2nd gen Colorados/Canyons in 2014.
To me, (considering the fact I have a manual transmission) they act more like a mini-Hemi, so they need high RPMs to get into the sweet spot of their "powerband". This is probably not so noticeable with an auto transmission I imagine unfortunately, unless you have a tune on it/tweaked transmission shifting points via the PCM. After hitting 2.5-3k RPM is where I'd say they start getting some good torque, at least that's what it feels like on my truck anyway, haha.
2006 Chevrolet Colorado Regular Cab Black w/sports pkg., 2WD, 2.8 I-4 w/ Manual Trans.