They achieve the same result, just with a little different method. On the N-series bpdufilter looks for any ports that are set to portfast, and disables the transmission and reception of BPDUs on those interfaces. With the 5548 bpdufiltering looks for ports with spanning tree disabled. There is not a command on the 5548 that will look for interfaces in portfast mode and filter the BPDUs.
It looks to me like the "spanning-tree bpdu filtering" on the 5548 the same as "spanning-tree portfast bpdufilter default" on the N series switches -- is that correct?  If not what is the equivalent command for "spanning-tree portfast bpdufilter default"? Ken
Is the spanning-tree bpdu filtering on the 5548 the same as "spanning-tree 
portfast bpdufilter default"