malloc & placement new vs. new

Question

I've been looking into this for the past few days, and so far I haven't really found anything convincing other than dogmatic arguments or appeals to tradition (i.e. "it's the C++ way!").

If I'm creating an array of objects, what is the compelling reason (other than ease) for using:

#define MY_ARRAY_SIZE 10

//  ...

my_object * my_array=new my_object [MY_ARRAY_SIZE];

for (int i=0;i<MY_ARRAY_SIZE;++i) my_array[i]=my_object(i);

over

#define MEMORY_ERROR -1
#define MY_ARRAY_SIZE 10

//  ...

my_object * my_array=(my_object *)malloc(sizeof(my_object)*MY_ARRAY_SIZE);
if (my_object==NULL) throw MEMORY_ERROR;

for (int i=0;i<MY_ARRAY_SIZE;++i) new (my_array+i) my_object (i);

As far as I can tell the latter is much more efficient than the former (since you don't initialize memory to some non-random value/call default constructors unnecessarily), and the only difference really is the fact that one you clean up with:

delete [] my_array;

and the other you clean up with:

for (int i=0;i<MY_ARRAY_SIZE;++i) my_array[i].~T();

free(my_array);

I'm out for a compelling reason. Appeals to the fact that it's C++ (not C) and therefore malloc and free shouldn't be used isn't -- as far as I can tell -- compelling as much as it is dogmatic. Is there something I'm missing that makes new [] superior to malloc?

I mean, as best I can tell, you can't even use new [] -- at all -- to make an array of things that don't have a default, parameterless constructor, whereas the malloc method can thusly be used.