Selenium v2 more closely approximates the user experience compared to Selenium v1. It uses a WebDriver API and browser-specific drivers instead of a proxy-based approach. Tests written for Selenium v1 need to be rewritten for the new WebDriver API. Issues may arise from hidden or non-visible elements not being clickable, and from inconsistencies in how different browsers generate mouse and keyboard events. Developers need to add more synchronization using implicit and explicit waits to account for variances in how quickly browsers execute actions.