BFD vs BGP timers

We're having discussion of changing BGP timers rather than using BFD and I'd like to ask for your operational experiences on this. We have downstream BGP customers physically attaching to an L2/L3 switch that doesn't do BGP. So, we logical pipe them through MPLS to a router that can terminate the BGP session. The logical pipe never goes down, so the only thing that would cause the customer's session to go down in the event of a physical layer problem is the BGP timer. This is not acceptable, so I have been using BFD to time out the BGP session. However, we have limitations on the BFD pps and folks here are wanting to change the BGP timers instead. What're your experiences regarding this? scott