I flew to ACE with BA in late April. The flight was showing as being operated by a A319 until a couple of days before. Then it was changed to a 734.
The crew said that it there had been a number of flights to PFO, TFS and ACE operated by the ex BD A319's that had encountered weight restriction problems.
From ACE a number of flights were required to make a tech stop on route to take on fuel and on the PFO this has meant on occasion a number of bags have been left behind.