What, so you mean that after meeting up with Russia, they should have just attacked Russia? The reason why the Allies didn't take the whole of Germany is because Russia had captured more then its fair share of Germany and had even passed Berlin on their way to destroying the Third Reich. The War was over, there was no need to continue on.
Well no, we all have the technology now that the Nazis had back then. But if we had all the technology back then, then the cold war would probably ended much earlier. A lot of the cold war was a technology race (every time about countering the russians with technological more advanced weapons/...): the space race, the stealth bomber, russian inventions, nuclear weapons, ... . Other then that as a result that we would have been advanced much further in those fields of science (that we captured from the germans) much earlier we would stand much further now in science because we would not have lost time.
No the war was not over, at least that was the feeling after the war. Both the Allies and the Soviet Union have been on the brink of war until the end of the 'cold war'.
The thing is that the allies agreed with the Soviet Union that they should take berlin and the rest was also agreed in the same way: the allied forces had a very weak negotiation, they surrendered much territory to the Russians even before they got to take the territory. I agree that Berlin would have taken many casualties anyway, but in this case the soviets themselves were the reason for it because they behaved like beasts in all German areas. That is why they fought to the death and why germans were much more eager to surrender to the Allies, then they were the russians (they pretty much fought to the death). If the allies would have taken Berlin there was even a chance that they would have surrendered before the capture (the man that had the actual control over the german forces was not hitler at the time, it was a man that would later negotiate the real surrender and already tried to surrender germany to the allied forces but was arrested by a german soldier while he was on his way to the allied frontline). The war effort then determined who had right to what territory, the Russians had pretty much everything they captured by battle. The fact is that the allies pretty much gave Berlin and a lot of German territory as a gift to the soviets because the Allies were so close to those borders that were agreed upon that they had to wait days or weeks for the soviets to catch up (all generals were frustrated that they would just wait for the Soviets to take the rest). This kind of attitude is now blamed generally on the french now, that they are not reliable and they don't want to fight but at that time all the allies behaved like that by letting the soviets do the work and it made them feel superior towards the allies because they know it. When the allies went to berlin for the first time the Soviet forces acted with disrespect towards the allied forces, because they knew they took Berlin and they claimed the victory over Germany and not the Allies.
So I think it would have been better for the allies if they would have taken more of germany and even Berlin, because it would have shortened the time of the cold war in our favor. And it would have resulted that some of the technology we have invented just recently, would already be finished a couple of years ago thx to the german technology we would have discovered and not needed to reinvent because we lost years by reinventing things that the germans already had invented. Therefor I think it is a mistake, even though we have won both the cold "war" and WWII.