Due to the 24/7 nature of our business my company is quite reluctant in moving to 184.108.40.206 patch. We are still on 220.127.116.11 for production stability reasons.
In the past months I have come across a few issues and Oracle support always recommended patch 4 because most of them were fixed in that patch anyway.
My question to you guys is, if you have faced any issues after putting the patch 4. Going thru all the documentation (bug fixes) on OTN for all the versions/upgrades after 18.104.22.168, throws up lots of information.
One issue I do remember was Exp/Imp was giving wrong results (in some unique cases) in 22.214.171.124 while this problem didn't exist in 126.96.36.199. The workaround was to use 188.8.131.52 exp/imp binaries (not acceptable to management)
Are you aware of any more such issues that broke things in 184.108.40.206 that were fine in 220.127.116.11
There were a couple of issues with the 18.104.22.168 patchset, but 22.214.171.124 has been pretty stable. I have been on 126.96.36.199 for about 6 months on two of my production boxes and there have been no "show stoppers". Of course, I have applied about 6 one-off patches to 188.8.131.52 to correct ORA-600/7445 issues, but all-in-all, I think it is pretty stable.