Suggest to stay at 2.5 for now. -- 2.51 is internal version not released, only on some newer PCBoard models from the factory, not designed for older h/w.
Newer eboots are coming soon, at that time the update and them should be tested together.
Yes, because due to some changes that Sony has done with 4.11, it is best to uninstall first, all forms of ReactPSN, Spoofer or other tricks and allow the TB dongle to do the work for you with this update.
In order to provide a feature rich experience for users we will add support for some popular programs/applications in TB CFW 2.61 which will be released within the coming days. We thank all TB users for their continued support and patience whilst we develop feature updates and firmwares.
Anyone who has modified their TB CFW and is experiencing freezing, may simply revert to 2.51 TB FW using the special fw file attached here and reinstall the 3.55 CFW DG on their console. This will completly fix any freezing issues. We kindly remind TB users not to modify the TB console CFW 3.55 unless we explicitly state in the accompanying notes included with upcoming TB 2.61 fw that the program/application is supported.
There is no real need to update currently, as there are no new EBOOT patches that have neem released with this update. It is recommended that official True Blue users wait until the update is officially re-announced before installing.
Download Link: TrueBlueUpdate-2.51.zip (for newer dongles)
ALTERNATE DOWNLOAD for 2.5 TrueBlueUpdate-2.5.zip (For older dongles)
News Source: PS3Crunch