Using Bitcoin brings about extreme speed in transactions which in never possible before its existence. To put simply, it provides almost perfect convenience to transaction speeds but that in itself comes with a fair measures of security issues which can be solved by being more cautious.
Talking about "extreme" speed, not all the time bitcoin will give you an extreme speed in transactions. Because it's one of the issue right now, many are experiencing problem with this matter. But for me, people should use bitcoin right now because the chance making them rich in the future will be gone if they aren't going to get into it.