I have the standalone unit and other than the painfully slow 100mbit Ethernet that's too slow to upload ISOs and which also doesn't work with many modern switches - it's really nice for the price.
The problem with a pcie one for me is that modern motherboards suffer from having hardly any PCIe ports - and when they do they're mashed in close to each other essentially making one useless if you have a decent GPU.
I run this in a 1u rack. Rather than mess with a pcie riser, you can power the kvm via an internal USB header from the motherboard to the kvm USB header directly for both power and HID.
The problem with a pcie one for me is that modern motherboards suffer from having hardly any PCIe ports - and when they do they're mashed in close to each other essentially making one useless if you have a decent GPU.