I haven't found it that bad. I only have 10 minutes at a time and the beautician always puts a soothing cream on my face afterwards. It is a bit red for 10 minutes but is then OK.
However, how painful I find it varies a lot and I think has a lot to do with how I am feeling, if I am feeling a bit under the weather or stressed it is a lot more painful than when I get a train of thought going that makes me oblivious to everything else. but given what the alternative would be (for me), I am prepared to suffer.