Originally Posted by alecE
Will see if this recurs on 0.7.1 - just a passing thought, is *all* the metadata being re-sent or just the metadata for the modified item(s)?
The answer currently is 'that depends'.
0.7.0 & 1 have a problem where corrected metadata for matched books is sent back to the device, then ignored. This isn't a problem for epubs that were put on the device by the instance of calibre currently used, because they will have the necessary ID in them to avoid sending the info again. Other formats aren't so lucky.
To give hope: there are some changes that should appear in 0.7.2 that help.
1) the problem described above is fixed. Corrected metadata will be put in the device cache, and therefore not sent again and, more importantly, not converted to XML again.
2) several performance issues were fixed in the driver.
Before these fixes, on my machine with 400 books (mostly epubs but ignoring the optimization), connecting the device took 14 seconds. Now it takes 1.6 seconds. Adding a book varied between 60 and 80 seconds. Now it takes 7. Given that my original numbers are so different from yours, I can't say what improvement you will see. It will probably be substantial, but we will need to see how much so.
Another 'improvement' is the addition of much more detailed Sony driver performance tracing when using calibre-debug. The information should help localize where the problems are, if the problems remain.