This should not be the case iCamp. MC12 should beat-or-tie MC11 in "speed tests" nearly 100% of the time, with identical libraries. About the only thing I find slow in MC12 is the automatic thumbnailing processes (which, can be a killer if you have a lot of RAW images in your library, or a lot of movies on a slow network drive). I generally try to run a manual Thumbnail build on my library once every other week or so overnight, to avoid as much of the background thumbnail building as is possible. You can do this via: Tools --> Options --> Tree & View --> Thumbnails --> Build Missing Thumbnails.
Assuming that doesn't clear it up, you'll probably want to check the logs. Do you have logging enabled (Help --> Logging)?
If not, go ahead and enable all of the events, and reset the log and restart MC12. Try to recreate some of the steps you mentioned (including startup) and then immediately review the log activity. The numbers along the left edge are times in milliseconds, and longer multi-step processes are also timed when they finish.
Try looking for specific items that take a very long time to complete. If you find something that looks unusual, or is taking multiple seconds to complete, then post the relevant "clip" of the log here, like this:
0000141: 3916: Database: MCDB::Unload: Start
0000141: 3916: Database: MCDB::Unload: Unloading
0000141: 3916: Database: MCDB::Unload: Resetting info
0000141: 3916: Database: MCDB::Unload: Finish (0 ms)
0000141: 3916: Database: CMediaFileIOLoad::Load: Loading: C:\library_data\andoria\mediafiles.jmd
0000141: 3916: Database: MCDB::GetRMDB: Creating object
0000141: 3916: Database: CMediaFileIOLoad::Load: Loading: C:\library_data\andoria\removable.jmd
0000156: 3916: Database: MCDB::GetPLDB: Creating object
0000156: 3916: Database: CMediaFileIOLoad::Load: Loading: C:\library_data\andoria\playlistx.jmd
0000156: 3916: Database: MCDB::GetMFDB: Creating object
0000156: 3916: Database: CMediaFileIOLoad::Load: Loading: C:\library_data\andoria\mediafiles.jmd
0000188: 3916: Database: MCDB::GetBSDB: Creating object
0000188: 3916: Database: CMediaFileIOLoad::Load: Loading: C:\library_data\andoria\browser.jmd
0000188: 3916: Database: MCDB::GetVSDB: Creating object
0000188: 3916: Database: CMediaFileIOLoad::Load: Loading: C:\library_data\andoria\view state (index).jmd
0000266: 3916: Database: MCDB::GetCPLDB: Creating object (0)
0000266: 3916: Database: CMediaFileIOLoad::Load: Loading: C:\library_data\andoria\curplaylist.jmd
0000266: 3916: Database: MCDB::Save: Start
0000266: 3916: Database: MCDB::Save: Saving (bCleanDB: 0, bForce: 0)
0000281: 3916: Database: MCDB::Save: Finish (15 ms)
Which is where my library is loaded while MC is starting up. Bear in mind that some processes, such as downloading Podcasts, will take a long time to complete no matter what. These activities typically don't block normal program operation though... Another thing that would be helpful for trying to diagnose the issue is more specifics on the system you're running it on. EG: System Stats (RAM, OS, CPU, and Other running tasks), where are the media files located (what type of drive, and connected how), where is the database located (same), and anything else that could be impacting the performance of the machine.
