Lawsuits made them change a 70 to an 80. The firing pin safety is the result. And whatever you get you are doing just fine. You can be a critic once you have both. I have held and fired more 70s than I can recall. Yet my first ownership and firing of an 80. Did'nt feel any different at all. It takes a trained eye and experience to know the difference.
I'm not aware of any actual lawsuits involving Colt. I just think it's a pretty safe bet to assume that Colt realized the potential and decided to do something before it happened. In military service there were several incidents where a dropped M1911A1 discharged, although they were likely due to worn parts like weak firing pin springs (having taken a few M1911A1s apart to find the FP spring was limp as a noodle leads me to this conclusion).
As far as preference, I find that a pre-Series 80 w/o the FPS is safe as long as you use an extra-power FP spring. Aside from that, it's all a matter of opinion.