I am doing my M-Tech (by Research) in IT from NITK Surathkal (CGPA 8.5/10 in M-Tech and 7.9/10 in B-Tech) and am applying for PhD in CS/IT (area: Virtual / Augmented reality, Human-Computer Interaction) at US universities for Fall 2014. I have almost 2 years' work experience at Infosys Ltd. as software engineer, one publication in an international journal and expecting one or two more at international conferences some time soon, besides a sizable list of awards and achievements. I took the GRE day before yesterday and am still to receive my essay score (expected 4+/6). I have already opted to send my score to Penn State, Maryland-College Park, California-Irvine and Northwestern. I will be taking the TOEFL some time around 2nd week of September and am confident of getting 90+ therein. I am interested in joining R&D based companies in US after my PhD. Should I apply to any other (significantly) better universities than than the ones I have already opted to send scores to so far?