No, I literally made my own hand-soldered Pi Port -> PCIe adapter. That's to plug a 2x25Gbps programmable NIC, so no bandwidth needed because the NIC does all the work. All I needed was something to power up the nic :D

As for bandwidth, well, it's one lane of PCIe gen 2. This won't win any races but can be useful to access exotic hardware not available in usb or if you don't care about bandwidth. (e.g. HBA with many drives for mass storage without speed requirement).