Currently I am using same mobile. The material and construction quality of lumia 540 are excellent. The volume and power buttons are on right top of the mobile. Sound contains level 0 to 10 for ringtone, notifications and 0 to 30 music and videos. It has 5 inch screen which help you to hold it with one hand. The mobile has dual sim option and micro SD upto 128GB memory. Currently now I am using Windows 10 software. It was simply superb with new style of apps, lockscreen and lumia store. Updates are required for lumia for better runnig of applications. There is wi-fi, cortana and no of shortcuts for every app. So I recommend you to trust lumia mobiles.