Vantaggi
You will learn a lot in terms of technical work, whether you are a developer, tester, network engineer, BA. Lot of exposure to different-2 work. In an MNC, you will not learn this much as a fresher, because you will be limited to your daily job only.
Svantaggi
No trainings what so ever. You have to do all the things yourself. This is good but some times annoying also. Managers are completely non-cooperative, means you will be feeling like hell after 1 year. Loads of politics. You have to do the work assigned to you in time you are asked, along with it, you have to do extra work too. You will be asked at the time of your appraisal, what new or extra you have done except your Assigned work. Appraisal process is really the worst. But Yes, 1st appraisal will be good, but the process will annoy you very badly.