I stayed here 3 months when I landed in the region, had a studio there. The apartment was ok nothing really to complain, even though it is not the best value  for money in my opinion. My rent was quite expensive,900 €, but it was ok for me as it was a temporary solution. If you plan to stay longer, maybe consider other options.

I was also very disappointed by the company behavior as when I left I was charged for 120€ cleaning fee because they said curtains was dirty and they washed pillow I haven't even used and I paid for that. Quite dishonest to me, I have never had any bad experience like this with apartments I have left before and after this one. So I highly recommand you during the "état des lieux" to note everything that is not in a perfect condition and to report. This might take some time as it is furnished apartment and the employee may pressure to do it quickly as he has other things to do but really take your time and note everything and take some pictures.

For the location, it is not the topic of the question, but I will give my opinion as it is the opposite of the previous comment. The building is very well located in the city center and the center is very pleasant to live, there are lots of shops, supermarkets, it is the most lively area in the French side. Probably not the safest everywhere, but the center neighborhood is ok.

Hope it will help you.

Perhaps not the "safest" (not sure what this is being compared with) but a real city, with plenty to offer and not just a dorm like all the other small boarder towns on the other bank. Plus the extension of the train and the tram lines being built (end of works scheduled to be in December 2019) will put Annemasse at 18 mns from City centre, which can't be beat by a long shot from Ferney or Divonne, that only really have their Sunday markets to speak for them.