I totally agree with the others opinions about a separate interface being better in the long run, but if it ain’t broke don’t fix it either.
I play guitar through amp Sims hosted on C3, So latency is probably more important to me, versus sending MIDI from a keyboard controller.
Even so, I used the Scarlet 2i4 for several years, I think you can still pick one up for a couple hundred. That’s not to say there aren’t others, but I found the Scarlet to be pretty darn good for the money, and their latest round of drivers improve the latency. However, currently I’m using the PreSonus quantum 2626, which is by far and away the best interface I’ve ever used. It’s firewire, which is mostly why the latency is so low. But the 8 ins and 8 outs can be very handy, not to mention the price and the audio quality. It’s been rock solid for almost 2 years now…
Another advantage to an interface that I found particularly effective, is the ability to simultaneously run an input from your mixer aux send into the interface and into cantabile. Then you can set up a separate rack for vocal effects. Now you have total control over almost any vocal effect you might need, and you can program effect changes very easily. For example, we do Smooth by Santana. Even though I have a digital board, I can’t control the EQ through MIDI at all, so I can’t get that “radio”/all mid-range vocal sound, and then switch to a normal EQ for the next section of the song. But in cantabile, I just have a vocal effects rack, and a state with the mids, and another with normal. This is all while playing guitar etc in cantabile. And if you’re using a backing track, you just set a binding at the right point on the timeline.
To do this you need a dedicated vocal input on your interface, and a dedicated output for that effected vocal to go back to the board. And of course a mixer channel for the vocal effect, or a effect return if your mixer has that.
And I’ve read of many others who do the same thing, in fact that’s where I got the idea!
Tom