I am used k4 note with lollipop 5.1.1 version
I compared both marshellow and lollipop .Only find out the difference between some interface and increase more finger print option otherwise no change in marshellow. Better is lollipop 5.1.1 than marshellow. I think upgrade is not good for k4 now. it is a very good phone .its work fast and many app can we install in this.it is a best mob in this price yeah sometimes its too hot in front side but everything is OK so guys whats up .take it is in a easy way .buy and enjoy I’m certified becz I’m using now before 8 to 9 months no plbm come .