In Korea, US-made Sherman tanks faced off against Soviet-made T-34's, which were comparable tanks of the WWII era. Also in Korea American B-29 bombers (which devastated Japan during WWII) were shot down by Soviet-made MiG-15's, actually forcing them into a night-time only bombing role. The US would then introduce the F-86 Sabre to the battle to counter MiG's early dominance.

Your question is kind of difficult because it's hard to say for sure that the US/Germany were "technologically equal". In some ways they were, in some they weren't. For example off the top of my head the Germans didn't have an effective heavy bomber ever produced in large numbers like the Americans did, nor did they have any aircraft carriers which the US churned out during the war. Germany did have some stuff that US forces didn't have such as the V-weapons, or heavy tanks like the Tiger, however these lofty projects tended to be wasteful or over-engineered. Technological advantages over the Germans (as well as the well known industrial and production advantages) were part of why the Allies won the war.

No they were not, let me elaborate. I think it could be argued that Germans did have the skills and know how to produce the same weaponry the US produced, or even more advanced in several cases, V1, V2, snorkels for submarines, jet fighters and super tanks are few examples. They would differ for some reasons, on one hand (and one of the most important) is that Germany lacked the overwhelming industrial capability of the US, Germany was still a highly industrialized country but simply not able to access the raw materials and produce the same quantity of output. On a different level the degree of innovation would also vary according to the strategical situation of the country. The US developed a large unique Navy with an impressive number of aircraft carriers (and very effective too) but because they were conditioned by 2 oceans, Germany was not it was more of a land/continental power. So based on engineering skills I'd say they were matched, most of the German rocket scientists would end up in the US developing the US Space Program. On to your question: Well, the Soviet Union may have seen in retrospect a bit underdeveloped as compared to the US but its scientific community has always been 1st class.We still use their ballistic missiles as launching vectors for our civil space missions, they put robotic probes and explorers in the moon and several planets way before Mars pathfinder et all. We never saw a confrontation of the 2 powers (luckily) but we know their weapons and technology has been used extensively around the globe in proxy wars. For instance AA Soviet systems gave a very hard time to Israeli pilots during the Yom Kippur war, losses were very high. On the contrary mainly FRENCH manufactured planes decisively defeated Arab Soviet equipped air forces in the Six Days war, but training played a crucial roles. India and Pakistan equipped with a variety of Soviet and US & Western equipment have fought several wars and all results are kind of inconclusive for the purpose of our discussion. In general Soviet equipped armies have been poorly trained when compared to US and NATO or the confrontation has been asymmetric. We would be comparing apples to oranges, moreover, the 2 countries (URSS and US) had different tactics, strategies and operational methods which in fact conditions the weapons development. Russia and China are on the raise again and some of the assets seen are quite impressive, the latest generation of MIG and Sukhoi fighters seem quite an adversary for the US, and China is catching up with similar models as well as developing a blue water navy. In addition you do not need to technologically match everything the US has, you can just match one of the areas to be a threat, like India or Pakistan with nuclear weapons. Bottom line, while there is no match yet for the US and threats remain asymmetric the US still needs to keep up the technological development pace not to be caught off guard in specific areas.