Haven't tried bluetooth, but I've seen several improvements.
Facebook: Seems to be connecting without errors now, but still too early to tell.
Vlingo: Wouldn't work with built in mic on .190 and I had to finish setup using bluetooth. With .238 Vlingo is working as advertised.
Viigo: No issues in .190 after downloading it from Download | Viigo
. No issues in .238 after upgrading. No reinstall after upgrade needed.
TMO myFaves: myFave interface still doesn't work, and this appears to be an issue on TMO's end.
.238 booted in far less time than .190 and so far seems to be snappier on my end.