I love my No No. I think the bad reviews were from those not taking the time to use it regularly and properly. I have both models and both are great. It often takes more than 4 passes to remove hair but the buffing will remove the weakened hair and the roots will still be treated. You may even have to shave at first if all are not removed. When I first started to use it, I used it faithfully 2 or 3 times a week then after 3 months it malfunctioned and I had to send it back for a replacement which did take 2 months (my only complaint). At that point my leg hair was only showing about once every 3 weeks or so which is far better than shaving at least 3 times a week and the hair is very fine and hardly noticeable. I hadn't used it on my face yet though. When I got the replacement I was rather lax for about 6 months but I did notice the time between hair growth was a month or more now. For my facial hair it took a little longer and that was probably due to the curves in my face but now after about 8 months of fairly regular use, it hardly grows much. I never noticed a strong burning hair smell - it is slight and isn't significant. Now most of my leg hairs are not growing back and the only place they are are on my knees, backs of my lower thighs and inner upper thighs and that is only about every month and they are the courser hairs.
I would say that if you want a miracle to happen overnight then it is not for you but if you are willing to read the instructions and use it regularly at least at first then you probably will not be disappointed.
For me it was well worth the effort.