Hiya!
I wrote an answer discussing the relative advances of the Western allies and the Soviet Union a long time ago. I'll copy the relevant section below:
A critical point that mustn't be ignored is the political aspect to the Battle of Berlin. Allied forces halted upon reaching the river Elbe around early April. The reasons for this remain a topic of debate, but it is widely accepted that the main reasons were thus: Neither the strain placed on Western-Soviet relations nor the projected casualties were worth the prize of Berlin.
As Beevor writes, " 'The lair of the fascist Beast' was the key symbol of victory after all the Soviet Union had suffered, and Stalin had no intention of allowing any other flag to fly over the city.".^3 Stalin's determination to be the first in Berlin, both for political and strategic reasons (Eg the extension of communist influence) meant that it would be an extremely dangerous political move for the allies to race Soviet forces there. In hindsight, this decision may have been politically naive, and certainly contributed to the state of Europe during the Cold War, but in the context of WW II, it was understandable.
Eisenhower was also prompted to call a halt to the advance and let the Soviets take Berlin due to the concerning casualty estimates he received. US General Bradley advised him on April 14 that taking the city would result in at least 100,000 allied casualties, though he later admitted that this estimate had been far too high.^4 He was, arguably, somewhat vindicated, since the Soviets suffered roughly 90,000 dead and 250,000 wounded in the combined battles of Seelow Heights and Berlin.^5
Hopefully this has done a little to shed light on the context of the two fronts and the reasons for the Soviets being the first to Berlin. Not exactly a world-class essay, but I'm procrastinating on an essay I really need to be writing about the Winter War.
Nowadays I procrastinate on other topics by writing essays about the Winter War here on /r/askhistorians. How times change. If you have any follow-ups, please don't hesitate to ask!