I've tried a number of the Flickr modules on a website I'm working on.
The biggest problem with most of them seemed to be a Flickr issue: when you go to the lightbox slideshow, many pictures come up with a message saying the picture isn't available. They show up in Flickr, though. The solution other extensions tell you is to reload the pictures to Flickr at a more consistent size. Explain that to the client who sees them displaying fine on Flickr, but not in their site.
jFlickr displays all the pictures my client has uploaded, no problem.
I did have a problem in using multiple instances on one page.
A visit to Joomla Bamboo's support forum didn't have a solution, so I posted the details...they released an update to fix it the next day.
If you're looking for a Flickr module, this one gets my highest rave.