I had been using Samsung android phones for a while.I had got irritated by the fact that its battery get used to get drain quickly.and android system was good but not the best.its mainly good for games I have come to believe. I bounced on Lumia 20 series after good feedback from friends. Lumia 10 series was not good.
Few things I like about Nokia Lumia 620 -
Battery life is good. It lasts 1.5 days with 3G. Without 3G it lasts 2 days.
Unlimited music downloads of any music - past or new - with Nokia store.
Windows 8 is cool.They have given attention to terrific details.
Nokia durability - nothing happened even after my phone fell for 2-3 times.
It has all the apps which you require - money-control, YouTube, LinkedIn etc.
Xbox games - Free Xbox games are good.
Best is city lens feature - you can find anything in your locality by pointing the phone in that area
Maps and navigations is good.this aspect is worst in Android.
Few things I dislike-
Less apps. However all the apps which are required for business use are present.
Camera quality is not good in low light conditions.
Verdict - Overall a very good phone. Highly Recommended. Now they have come up with schemes wherein you can replace old smartphone with Lumia.