I think the capture of Soviet tanks early in the war was more along the lines of what happened with French tanks, more than in later situations. The USSR was caught in the middle of a major military transition, ammo production halted to work on a new gun, and the purges still fresh so a lack of leadership. Large numbers of Soviet tanks started off with limited ammo and fuel, and were simply abandoned when the crews slipped away after dark making them easy for the Germans to repair and operate.
The KVs get kind of a bum deal, now often looked at as kind of also rans (T-34 is armor's P-51 Mustang) but in 1941 the KV-1 & 2 were way more tank than anything the Germans had, and there are many examples of single tanks holding up the German advance for hours until they ran out of ammo / fuel.
In North Africa enough Italian tanks were captured to outfit an entire Australian unit (I think it was around 100 tanks).
During the Ardennes offensive (Battle of the Bulge) the German's tried to field a unit of US vehicles, but could only come up with about a dozen tanks and armored cars and had to use disguised German vehicles to fill out the rest. With the priority given to this, I would guess that indicates they simply didn't have many.
I know there are a few photos of captured tanks with Japanese markings, but I've never read anything suggesting these were used for much beyond evaluation or local opportunistic use of individual vehicles.