Months ago I upgraded my Mac Mini to include a 240 GB SSD to use as a boot drive. At the time I was unfamiliar with TRIM. I noticed a slowdown in function over time and and implemented TRIM. Since it has been running without TRIM months would a full re-install be necessary to get read speeds back up? I also have a complete disk image created by Super-Duper, could I use that?
No, no re-installation is necessary. A full disk image restore would be counterproductive, because it’ll probably write to every sector, marking them all as used again.
SSDs regularly optimize their internal data structure, if enough free space is available. This could take some time though, and the performance might be even worse during the optimization process.
Upgrading to Mavericks is the easiest way to install, but I always prefer a clean install, copying your stuff back afterwards. Upgrading keeps a lot of unnecessary files/config from the version you upgraded from. There is a setup option to do a clean install but save the current user data in a folder. This is always my preferred method.