It is our ambition to make GitLab.com as fast as GitHub.com but currently we're slower. Please see https://gitlab.com/gitlab-com/infrastructure/issues/59 for more information on how we're working to improve this.

This depends a bit on what parts of GitLab(.com) you're using. For example, viewing issues should generally be as fast as GitHub.com (http://stats.pingdom.com/81vpf8jyr1h9/1902794/2016/10 vs http://stats.pingdom.com/81vpf8jyr1h9/1902795/2016/10). Other parts may be a bit slower; pushing for example can still be a bit slow at times.

I'm on the East Coast. For a while GitLab was quite slow. Much better now. They made a lot of progress in the past 3 or 4 releases. However, I agree that GitHub is still better in terms of performance. Now, I put things like tooling, pricing model, features, and ethic of the company above performance :)

Don't put your hopes up too much. GitLab does not even have half the community that GitHab has but their service is already a multiple times slower. From my experience if something already starts off really badly, then any attempts to retrospectively fix major issues in their core system rarely work out well. The more successful GitLab will be, the more their service will fall apart under its own weight. This is what happens when you aggressively undersell your service. GitLab are not magicians. Cheap remains cheap in the end.

If you're into self-hosting, you can check Gogs which is probably the most lightweight Github-like platform (but also the one with the least features)