Good phone for its price. You can refer my blog where I put up an unbiased review
No serious noticeable lag
I don't n never believe in using any form of SP on my phones ....in past 9 years using so many types I had hardly even a hairline scratch on them. I take good care of my gadgets. I had even proven in front of my friends n posted in youtube attempting to scratch a Note2 by dragging scissors, keys, blade across display n it came out intact. Infact you can find plenty such videos on youtube. Only material harder than glass eg sand n diamond will scratch display n chances of such hitting my phone is zero.