The Kimber firing pin safety prevents the firing pin from going forward if the grip safety isn't depressed. The Colt Series 80's release the block when the trigger is pulled. The S&W 1911 has one that is also GS activated.
The 1911 was around a long time without FP safeties. Personally, I wouldn't let the presence of a FP safety swing me one way or the other. If it was the gun I wanted and it had one, then I'd still get it.
If you can find a Series I Kimber for a decent price, it would be a good shooter to have. They are viewed as being of better quality than the Kimbers of today since they weren't making as many back then. That may or may not be true but I don't find any problem with my Series II's. Kimber DID go through a bit of a "development" (beta testing?) period a few years ago. They seem to be doing the same thing with external extractors right now but the vast majority of Kimbers are very good guns and great shooters.
You can open up a can of worms when talking about FP safeties and their value or need. Many believe they are "lawyer added" devices there just to lessen any potential liability lawsuits. Others say you can't be safe enough. What can't be argued is that almost all modern semi-autos have them. It's just when you make a change on a 1911, lots of folks look at it as if you changed the colors on the Stars and Stripes. It's a "don't fix it if it ain't broke" issue.