Upgraded today to 10.3.4 from 10.3.3 on my TiBook. No obvious difference in performance nor new problems.

Nothing broken that wasn't already broken. My USB Apacer Handy Steno 256mb (bought from Apple Store some time ago) which worked perfectly in 10.3.2 but didn't work in 10.3.3 (freeze on large file transfers with 'trying to queue to a stalled pipe' reported in system.log) sadly still doesn't work in 10.3.4 - same symptoms. [Usual hygiene precautions taken in upgrade - repaired permissions and ran DW before and after - and followed advice for USB in
http://docs.info.apple.com/article.html?artnum=107914 ]. Hope this report is informative to suffering Apacer USB owners who were looking towards 10.3.4 as a cure.