This thread has been really interesting for me. I've been using the Realist with my A.I. Coda for about 4 years (Series II). I supplement that with an AMT mic (actually, I think of the Realist as the "supplement").
Of course, the Realist doesn't transmit a sound that is exactly "crisp" -- and can be "muddy" at times. Given its location (under the "E" string foot of the bridge), its nature (piezo warmth), and its need for high tension, it's just not designed for clarity, crispness, "string articulations" or whatever kind of "detail" you might be looking for. That's why David Gage called it "the Realist".
Add that to the A.I. Contra (or Coda in my case): Now, I love the sound coming out of the Coda Series II. But I can also confirm the inconsistent results everyone seems to get (sometimes great, sometimes inaudible, sometimes boomy, etc). My experience this amp is great in smaller venues but has the limitations A.I. says it does. If you are playing in large halls or outside, or with a loud drummer and 2 electric guitars with their amps facing the audience, you may find you need an extension cab to supplement the Contra.
The other week I was playing in a restaurant in a stone cellar carved into the mountainside here in Switzerland, and the Coda was boomy even at very low volume and with the filter turned on up to 12 o'clock. It's just situational and different on every gig. I don't know what kind of amp could have sounded good there, but the audience liked my bass. Sometimes it doesn't sound great to me, but the audience can hear it well.
I use the AMT mic with the Series II Coda and it just sounds great. The Realist by itself cannot transmit a broad enough sound in my opinion. But together (one in each of the Coda channels, separate EQ and volume adjustments possible), it's for me a workable and really good sounding combination mainly for smaller venues. I have a new EA Wizzy cab I plan to experiment with for other larger situations where I need more projection.