How are these 3 HK P30's different???

Just going by the pictures...

The one on the top-left has a hammer but no safety, so with only that information, I would assume that it is a P30 Variant 3 (DA/SA with a decocker).

The one on the top-right has a hammer and a manual safety, so with only that information, I assume that it is a P30S (S = manual safety) Variant 3 (DA/SA with decocker and manual safety, with the ability to be carried cocked and locked).

The one on the bottom-left has a bobbed hammer and a manual safety, and it is a long slide version, so with only that information, I assume that it is one of the 500 P30LS LEM models, where it has the LEM trigger, manual safety, and the long slide. This one should be the most rare P30 available since they only made 500, but most people seem to believe a manual safety on an LEM equipped P30 is redundant. H&K only made 500 of these because in order for their shooting team in the US to use the P30LS LEM, it had to be a production model, and in order for it to be considered a production model, at least 500 needed to be sold to the public. It is doubted that H&K will produce this model again.

P30S - S= manual safety
P30L - L= long slide
P30LS - LS= long slide and manual safety

A P30 with a bobbed hammer normally indicates that it is an LEM model.

Contrary to popular belief, none of the current HK pistols are replacements for the USP. The USP isn't going anywhere; isn't being discontinued, etc.

Up until recently, many LE agencies in Germany were carrying the P7. I saw lots of P7s in holsters back in 2004. The P2000 was designed and built to be a new Police pistol for Germany, with the hopes that it would have taken a hold of other parts of Europe. The P2000 has found success in German Law Enforcement (hence the P7 police trade-ins) and here in the US with the DHS. It is a great pistol, but I find the recoil spring arrangement is not as effective as the full size USP's dual-captive arrangement. I own the DA/SA (Variant 3) and I don't care for the decocker location. They aren't very conducive to a high-thumbs hold due to the slide release location and protrusion. There's also no thumb safety option. Those would be my only criticisms.

The P30 is primarily a continued development from the USP and P2000, also with some similar design elements from the HK45 series. I don't care for this pistol at all. It feels good in the hand, but the proportions and balance feel completely off to me. There is a channel in the trigger guard that causes some rubbing/chafing on the trigger finger for a lot of shooters. The DA/SA versions have the P2000 style decocker and can be had with a slim thumb safety, which is neat.

I like the USP, particularly the .45 versions and the P2000 is a great little pistol despite its quirks. For me, the P30 and the HK45 series don't really cancel out the USP and P2k.

The DA/SA P30 models with the safety can be carried cocked and locked, and can be manually cocked.

There are very few LEM P30 pistols with safety levers, and these obviously can't be carried cocked and locked as they use a different trigger system.

You can't cock the hammer on the LEM models. The LEM trigger is H&K's offering to people who want a constant trigger pull from the first to the last shot, and it is not designed to be cocked.

On an LEM equipped H&K, after loading the pistol the trigger will be fully forward and the hammer will be resting on the back of the slide, just like a decocked DA/SA pistol would be. But the difference is that the trigger pull on an LEM H&K will be lighter, as it has some style of a pre-cocked mainspring.

The first shot out of an LEM equipped H&K will be a long and light pull, and the hammer will remain cocked unless you release the trigger. If you release the trigger, the hammer will come back down to the decocked position. If you are shooting and you only release the trigger until the reset position, the hammer will remain cocked.

There is no SA on an LEM equipped H&K.