A story from my experience.
When our team started - we were using planning poker by Mountain Goat. Since our team was distributed among 2 cities, we were short on options for estimation methods.
Thus, as our team was growing (in size of members and in terms of experience), we found out that the planning poker does not fulfill our needs anymore. Due to the scattering factor of team members, due to issues from different projects that have to be estimated during the same meeting, due to inefficiency for estimating large piles of stories - we switched from this method to another - the Team Estimation Game by Steve Bockman.
This method worked well for us, though the preparation time for a session increased (we didn't have a proper tool with the "online multiplayer" solution) - our scrummaster used Google Docs for preparing an estimation session.
Recently, our team has switched to the new Jira Add-On, that allows distributed teams to estimate stories using the described technique. Our scrummaster is happy, because he can quickly create an estimation session within 1-2 minutes. The Add-On is commercial, though (the method itself is free, thus ;))