The most helpful thing about this product was its ability to integrate with our accounting system so we could manage everything in one place instead of having multiple systems open at once (and forgetting what I had done).
It took some time getting used to but it's not too difficult now - if you're willing to put your mind into learning how best use things like tags etc then there are no real issues! We've noticed an improvement over other products when managing contacts/emails from day-to-day tasks such as sales calls or emails sent out by us internally within the organisation.