There is a distinct paucity of multi-port MIDI interfaces being released these days. It's not difficult to understand why, iOS and "In The Box" software-based music production setups are increasingly more common nowadays. But for those that wish to keep their hardware synths and effects connected to and controlled from a modern DAW such as Reaper, Ableton, Studio One, Logic etc etc. it can be difficult to find a reliable MIDI interface with more than 2/3 ins and outs, and full support for newer OSs.
It just so happens that Yamaha, being the awesome people that they are, released Windows 7 drivers (32 AND 64-bit! See the support page here they've updated them for Win8, even.) for this excellent little 6-in / 6-out MIDI interface. And I bagged one for about £25 on eBay.
It has worked flawlessly for me, in Reaper, but even more brilliantly it is truly multi-client. I've had Ctrlr, Reaper and MIDI-OX all running at once, playing notes from my master keyboard through the UX to a separate rack synth and not a single "MIDI interface not available" error in sight.
The UX256 is a tremendously rugged little half-rack unit housed in a metal exterior, and it feels quite substantial. Probably one of the best purchases I've made, and I'd heartily recommend it for anyone needing such an interface. There's very little information about them on the 'net, and only a couple of less than glowing reviews (Sound On Sound seemed to like it though). The new drivers have never given me trouble, and apparently it works in Linux, too. I'm not sure it'll work on iOS, but I'll update this post if I have any luck.