I've done this treatment a few times in other salons in the past and always felt very happy at the end of it. Because besides straightening it also removes volume.
For me it felt like she didn't know what the full process of the treatment is, and the final blow dry left my hair standing in every direction and looking very bad. Immediately after i went back home to wash my hair (which you normally would not do for 3 days - and not 1 as i was told) in order to try and reverse what they've done.
Moreover, I asked to sort out just a little bit hair on the sides, which is something that you would usually charge a bit extra for, now let's ignore the fact that she over-did it, because she knew i was growing my hair, but i was charged £15(!) extra for it. Probably because they knew i would never go back there EVER again with those results.