While I don't doubt the validity of the argument that it takes longer for a programmer to write correct lambda code in C++ (I have been using them since C++11 was released and still forget the capture list syntax sometime), it's not much more than an academic exercise to take some iterator-based code and replace it with higher-order function calls. It's unfortunate that all the tasks seem to be based around doing that though. I do think it is still reasonable to do this in C++11 once you know how - with -O1 turned on you can get basically the same code spit out using std::transform, std::accumulate, std::for_each, et al, as you would using a for loop.
It's also unfortunate to note that, at least in g++ and clang, there is still significant advantage to using lambdas over std::function and std::bind. Lambdas typically end up being faster in both compile-time and run-time, and end up generating less code. For these reasons I've found myself using them a lot more, especially anywhere I would have done some type of currying. This I do miss somewhat, but it's still leaps and bounds ahead of something I would have written in C++03.