Some quotes from the forum:
* large user base, this means a lot of potential translators
* bad workflow for getting translations upstream
* getting translations into a a new release requires manual intervention: It has to be downloaded from launchpad and added to LXDE's SVN.
* known to produce bad translations. This is the downside of being beginner-friendly
* More professional
* works with nearly every VCS: CVS, SVN, git, ...
* Translations are automagically pushed back to upstream's VCS
* Requires ether to be set up on a server (which also mean maintainance) or to use fedorahosted.org
* Smaller userbase
Elias: I think Transifex is better for this project, because the development of LXDE is not made in Launchpad. Launchpad is not (afaik) so flexible than Transifex.
cwickert: If we use fedorahosted we are bound to the Fedora accounts system (just like we are bound to Launchpad user management), if we setup our own transifex we can manage users ourselves more easily.
ogmaciel: I'd like to support the idea of using Transifex and host it with Fedora projects (unless someone has the time and hardware/bandwith). All pros/cons already cited are a pretty good list but the one that imho is the most important is the fact that translations should always be done upstream, and then trickle down to distros. Transifex plus a good quality control process before committing files (more about that later) will allow for a quick, efficient, and top quality translation process.