VC is definitely harder than SA. I don't think I made that without cheating.
But the Demolition man is possible without cheating - on a real keyboard at least, where you can have two steering crosses. Just practise a little with the helicopter, make some dry runs until you feet you are good enough to try the mission. It helps when you know where the barrels and the wall are in each storey, so that you can manouver in the blind, fly to the left, the right or backwards without adjusting the chopper first so you can see where you fly. Even though you will have a longer way, try to start with the top barrel and take out the gunmen. It sucks having enough time but a smoking helicopter and still two gunmen left.
Oh, the BOOOOOORING cheat doesn't help. Only makes the chopper slower to react and more likely to oversteer.