I am going to come down on the negative side. First, pictures are deceiving - the P7 is a BIG, heavy gun, not the small pocket pistol those who have seen only photos seem to think it is. But it works differently. It was one of sevral guns produced to meet the requirements of a West German state for a poliic service pistoll that would avoid the "mistakes" of previous designs. The mechanism is not necessarily bad, but different enough that its handling and functioning is different from anything else on the market at the time. If the P7 was the only pistol you had, you could learn to use it. But to someone who used many guns, H&K created a nightmare that went against the training and instinct for using other guns. Example: to keep the gun cocked, it is necessary to keep constant pressure on the grip safety,, and it requires a hard and constant squeeze to do that, unlike the easy grip safety of the 1911.
If pressure is relaxed, even for an instant, the gun reverts to a hard squeeze and trigger pull, even if the firing pin had been cocked previously.
I could go on, but that is one example of the gun's unique handling characteristics. In a gun fight, there is no time to think about how to do this or that or to remember how the gun you have is different and what has to be done to make it fire.
Yes, I have one; It is well made, well thought out, and (to me) highly dangerous; a gun you have to figure out how to use is not good in an emergency situation.
Jim