I've been holding off on posting my impressions until I had a little bit of time to really let things settle in and I understood what I was hearing. Here they finally are.
I got to use a prototype of the preamp a bit over the past two weekends. The first weekend I used it to track drums and then did a bunch of comparison tests with my API and Great River ME1NV. So it got used for drums, bass DI, electric guitar, and acoustic guitar so far.
Let me say this--I'm seriously considering selling my Vintech 1272 to replace it with a Pacifica. The preamp had amazing high end detail and I swear went another octave above the API and Great River. I was loving it on drum overheads, which were recorded with a U99 and U195 in fat mode. Transient response was much quicker than both API and Great River as well, which I really dug. Guitar sounded oh so right with the Pacifica...good midrange with my R121. Bass DI was right up there with both the API and Great River. I used a Fender J-Bass with some upgraded passive pickups. I think the Great River had the edge since you can dial in just the right amount of distortion. And the API felt like it went deeper. But the Pacifica sounded very similar to the GR at cleaner settings. Nice! I'm seriously sold on this unit just for drums and guitars alone. My overall impression is that it sits in there like a nice cross between Neve-ish and API-ish tones but with better transient response and more high end detail...overall very musical. I can see it being an extremely versatile preamp that would get a lot of use on everything. Which is perfect for a small studio like mine that can't afford to have 20 different specialty preamps.
After doing more extensive listening tests yesterday...
I'm selling my Vintech 1272. Done. I'm replacing it with the Pacifica. That was an easy decision to make. I recorded multiple passes playing my SG Standard through a Marshall JMP. I had two mics up--a Sennheiser e609s and a Royer R121. I did takes with both mics being recorded through both the Pacifica and the Vintech 1272. I then did some takes cranking up the input gain of the Vintech to get it in its sweet spot. For kicks I put the ATTY on the back end of the Pacifica to be able to hit the input transformer hard in a similar way to the Vintech. The verdict...the Vintech was slightly darker up top and was creamier in the low-mids, especially when the input was pushed. The Pacifica had a little more of an edge which I personally liked and a tighter sound overall. When I put the ATTY on the output and took off the input pad and slammed the input, then things really got kicked up a notch! That was the moment when I looked at the Vintech and said my goodbyes..."you've been such a good preamp, but now you have to go!"

I liked the midrange of the Pacifica much more than the Vintech when using the R121. I'm really looking forward to recording a lot of guitars with this thing!
I then did some bass (Fender J-Bass) with the DI, connecting the output of the first channel to mic input of the second channel. After figuring out the gain staging so that I wasn't getting nasty distortion, I was able to get a fatter sound than what was achieved with just one channel. However, I still preferred the sound of the Great River with the input gain cranked...it's just meatier and thicker, and sounds more tube-like overall. However, the Pacifica DI is no slouch and is totally useable. I would hesitate to use if for DI if the Great River was being used elsewhere. The API DI felt like it goes a little lower than the Pacifica though, but it's not as tight sounding. In a mix that would probably be a good thing in favor of the Pacifica.
Overall I'm really digging the color of this preamp. It's colored yet not overly so. The high end detail is superb. It's fast yet smooth and rich. Basically I'm sold! If anyone is interested in buying my Vintech 1272 then let me know...it's now for sale.
Brad