There might be a difference in circuit design, but its impossible to tell whether this is of importance for your whole setup or not.
My advice. Contact people in the shop. Get both and benchmark them against each other.
BTW .. If you consider buying the UFX, then I would directly go for the UFX II which will be shipped soon,
as there is a real advance in different areas compared to the UFX.
UFX II is the UFX+ without USB3, thunderbolt, MADI.
Differencies / advances: http://www.tonstudio-forum.de/blog/inde … 8-RME-UFX/
Sorry its written in german, but the list of technical advances should be readable for you as its mainly a list of technical things.
BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14