Almost any modern twin engine, starting by the not so modern Bell 212 will fly away AT SEA LEVEL, and this being heavy.
Recently a 212 had a PT6 blow (contained failure) up just as they were leaving the edge of the pad with 15 on board and 01+15 min fuel. He flew 60 miles back to base on one engine and the helicopter, and we are talking about a 34 year old helicopter (212).
I really don't know if it was heavy, I'm sure it was hot, but being the fact that the engine quit at sea level, I don't think the fact that it flew away is any measure of great performance, it's the least you could expect from a twin engine helicopter at sea level.
What's the performance like say above 6 thousand feet?