USAMO is excellent. MIDI generated by PC or even most MIDI sequencers is too jittery. I guess depends on what kind of music you make but after a while things will sound "off" compared to analog sequencers or built in sequencers etc.
You need to utilize an audio out for this. The USAMO box has a MIDI out and an audio in. It has a VST plugin too. You drop the VST plugin on a channel, and set its output (or in case of Ableton, use the "external audio effect" thing) to the audio out which goes into the USAMO box. Now you can add MIDI channels inside Ableton which can output to the Ableton channel with the USAMO plugin.
With the box, hook up the MIDI out to any MIDI to CV converter. I'm using a Mutant Brain and a Tram8, both are very good, I prefer the Tram 8 actually (8 gate outs, 8 MIDI CC outs) because of the MIDI CC options. There is 0 jitter this way, its really good, much tighter beats.