I think most people know the Soviets were less than kind to their enemies or anyone they percieved as their enemies or even rivals. What was done with American and British servicemen who were held by the germans, or hidden by the locals? Were they simply turned back over to the allies or would they be in turn held and questioned by the Soviets. Was abuse/mistreatment of allied POWs by the Soviets a thing?
I think this is quite a good question, I'd like to know the particulars for some of this.
Firstly I think you've approached the question with a serious case of post cold war vision. Yes, the Soviets weren't particularly nice to their perceived enemies, but this was world war two - the British bombed Dresden, the US dropped nuclear bombs on japan, the nazis let the jews starve to death or gassed them and noone quite knows just how many the japanese killed. I'd go so far as to say they were the second nicest of the 4 main players! The Soviets real dark time is the immediate aftermath of WW2.
Beyond that (and I'm going to generally stick with British troops here, as I can't say much about US opinion);
As I've said above, there was no real animosity between the average Soviet and Brit at the time. Most of the accounts of British troops meeting soviet troops in Germany go along the lines of 'we met up, shared cigarettes, swapped trinkets and struggled with the language barrier, then went our separate ways.' I believe the TV show Band of Brothers featured such a meeting, but it's been a while since I watched it. To most Britains at that time Russia was doing its own thing and not really a threat, noone thought they were bogeymen and during the war the media took a generous line on Stalin. Fascism was the problem, Franco, Mussolini and Hitler were that generations definition of evil. It was only really the establishments worried about the long term state of their systems position in both Britain and Russia. Many of the British fighting were Socialists or even communists, and saw the Russians as a much more preferable ally than the Nazis.
The Nazi prison setup was such that the majority of POW camps were towards the west (and captured by the Allies) and Concentration Camps were towards the East. map. When the Soviets did liberate a POW camp, the general order was to let the POWs choose - leave on their own accord or tear down the barb wire, feed them and keep them there until transport to the British lines was possible. This account of Stalag Luft 1s liberation seems pretty typical. It's fair to say the Allies treated Liberated Prisoners more harshly, but often for their own good (the Allies wouldn't let them wander off into a war zone or overeat if it would be dangerous)
The Soviets wanted not only their men back but ANYONE who was of a nationality under their control. Badly. So they were going to look after any Allied troops they did pick up, and get them on their way home so the Allies would do the same and more. As it happened, Churchill signed away the lives of millions - probably not something he would have done had the Soviets executed British POWS. Operation Keelhaul
So with Allied troops my general understanding is that the Soviets did exactly the same as the Allies, gave them a good bath and took them home, but I would dearly love to know of particular cases, especially downed airmen.
However.....
There is the case of Allied troops that were not members of the allied countrys. Most notably Poland.
Poland had a strong armed resistance and many of these guys had fled to England, fought for the Allies and came back to help liberate Poland. They were basically told to lay down their weapons and join the communists, or be shot as illegal combatants. Many of them had been in the forests and didn't know what was going on, many were killed, most were robbed and beaten. For the full story check out Anne Applebaums wonderful 'Iron Curtain' (2012), especially Chapters 5 and 11.
