Jakobud said:

The subdomain approach requires a separate Laravel installation.

you could actually use subdomain routing to use a single laravel project for both frontend and backend. http://laravel.com/docs/routing#sub-domain-routing

i think it's just a matter of preferences, i use both of them for different scenario.

i have the same challenge...this is what i am doing...not sure if this is best practice :(

Route::group(array('domain' => 'admin.mydomain.com'), function()
{
    Route::get('/', function() {
        return 'Hello admin!';
    });
});

Route::group(array('domain' => 'customer.mydomain.com'), function()
{
    Route::get('/', function() {
        return 'Hello Customer!';
    });
});