I use a 2014 rMBP. I need to keep Virtual desktop client running all through the day, Outlook for corporate email, and Safari for everything web-based. I can go though 70% of my day without needing to plug in. I really really really wish Apple add little more capacity so I don't need to be anxious about spending a work day on the move.

Except that you only get 10 hours browsing the internet, so unless your work consists of reddit and hacker news you can't really meet that target and I think most professionals would prefer more.