The old "GI style" 1911 is good, but there are reasons people have made changes. Most notable are the hammer, grip safety, slide lock/safety, and rear sight. Here's why...
The hammer is replaced with a target hammer for really two reasons: To fit WITHIN a beavertail grip safety (more on that next) and to keep you from catching the hammer on clothes, objects, etc. I mean REALLY, you don't cock a 1911 hammer with your fingers...you rack the slide back to do so.
The reason the beavetail safety replaces the original grip safety is because you want a VERY HIGH grip on the gun and you don't want your tender skin (between the thumb and forefinger) to get pinched between the hammer and safety. Believe me, it hurts. Those of you who've done a lot of Browning Hi-Power shooting can attest. Also, most current beavertail grip safeties copy Ed Brown's "Memory Groove" with provides a bit more extension for a crisper safety.
The GI slide lock/safety is extended for comfort and for ease of operation. Since the proper technique for shooting a 1911 is to have your shooting thumb ride on top of the safety AT ALL TIMES, it is much more comfortable to have an extended thumb safety.
Lastly, the original rear fixed blade sight usually doesn't provide a good sight picture for shooting. Many people replace the rear with a fixed low-mount/snag-free sight like a Novak. The notch in the sight is deeper and wider so that you see more of the front sight.
Springfield makes a fine 1911. Can't go wrong with either the Mil Spec GI gun, or their Mil Spec "Loaded" 1911. Personally, I'd spend the extra $50 for the loaded version.