They must not list all of their 1911s on the site b/c I don't see a 4" model. In fact, I don't see any steel frame 1911 45s on there. Either that, or I'm an idiot.
But more to your question, I owned a 4" Ranger II with the "bull barrel" awhile back. It wasn't reliable. Sample of one.
With STI just make sure you get one of their Texas made guns. Their lower end are made in the Philippines by Armscorp. Not saying they aren't bad pistols - they aren't. But if buying Armscorp you might as well save a ton of money and get RIA.
I have 2 sti great guns so they have reportedly cut their 1911 line to about nothing and are focusing on their 2011 and comp lines. the most recent purchase I made from them was an escort and frame is stamped korea. sti still does the fitting and assembly and warranty has not changed just reduces the tooling setup changes between models anyways hope it helps still great guns and the service is still there