Are you considering to switch to other VCS? Because switching to TortoiseGit/Bzr/Hg you will not be able to access SVN repositories. I'm working with GIT via TortoiseGit, but it is built on top of TortoiseSVN and have a similar performance.
If you are just looking for an alternative to use SVN, you should take a look at RapidSVN. It is still good and is way faster than Tortoise, it also runs on Mac and Linux.
Hope this helps!
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You should consider Git. It is modern distributed VCS made to be very faster and flexible, It have a very large and strong community. Many big projects are utilizing Git such as Linux (Kernel) and Ruby On Rails.
More about Git: http://git-scm.com/, http://whygitisbetterthanx.com/
