Several Cons, can't even describe all of them here, however I write few of them-
1> No Life - If you join Helios then your personal life will go for toss, during interview they tell you that they work from Monday to Friday, however, its a big lie, as soon as you join they will tell you that due to work pressure you should start working on all Weekends and on holidays till the project release which would be 6 months down the line, when you come first time on week end you will realise that whole company is working, so they lied to you during interview about 5 days a week job.
2> No Job Security - They do not tell during the interview that they are hiring employees on project basis, once the project is completed, they fire most of the people working on project, and as soon as new project comes they go on hiring mode again, you will always see vacancy in Helios since last few years because of this strategy. I have seen employees strength reduced from 33 to 5 once a project is completed. (and all of them fired citing work not up to the mark. Still wondering how come those 28 employees able to clear your interview process and suddenly become inefficient as soon as your project got completed.)
3> Increment - When the project is going on they gives their employees unexpected salary growth,(They do increment twice a year) saying they need to work harder, they could afford this kind of salaries because they fire them once project is over stating work is not up to the mark, even though the same employee got very good increment during the project development and was a great asset to the company before couple of weeks.
4> Cheaters - Cheat their customers with ghost developers, cheat their employees by not submitting their taxes (but deducting it from salaries) , by not paying their dues, not paying them or compensate for all work they did during weekends and holidays. Cheat the government by not deducting PF even though companies strength is around 100.
There are all sorts of cheating this company is doing which you can imagine of.
All the good reviews you see here, are all forcefully written by current employees to improve companies reputation which was already ruined because of their unprofessional behaviour.
(Height of creepiness - I have seen them even cheating with pizza delivery boy by giving him fake discount coupons, however it is irrelevant to this discussion, still it is one of the most creepiest thing I have ever seen someone is doing, specially an IT company)
5> Office politics - Company is having one of the worst office politics where your team leaders will get all the credits of your good work and will make you responsible for all bad things. ( this point could be consider as Pros of company, If you are good at office politics, this company might suits you)
In short If you do not have personal life and ready to work 15-16 hours a day, with out any holidays and weekends, if you do not want to learn anything new and do not expect any job security this company best suited for you (specially the bachelor guys who stay away from their families, who do not have any social network in new city and do not like to visit home), if you do not belongs to this category STAY AWAY FROM THIS COMPANY.