Hooked up the impact twin - updated drivers and firmware. Having a
Studiocat daw helped I'm sure, this whole experience was fairly painless. Initial testing on a current moderate sized project had a round trip latency of 2.9ms and using about ~20% less cpu than the replaced delta 1010. No clicks, stutters or ugly dropouts. TC has their drivers optimized for Win8/64 OS. (I was sweating the switch from pci to firewire)
Sonic wise, noticeable clarity improvement over the replaced delta 1010. I did not expect that. Matter of fact, I was hoping to just stay on par with the delta 1010's good sound. +1 bonus
The onboard pre's sound good for this type of system. I could use them and be happy. Still - I prefer outboard preamps. That within itself is why the Impact Twin along with a few others surfaced to the top. I needed an interface that allowed me to easily bypass the internal preamps. The TI allows you 4 line inputs (+adat and tos inputs) for situations like that. An interface without that preamp bypass routing scheme was an instant deal killer for me.
Thanks to JonD for his insight on the IT. He took quite a bit of time with me to explain his reasons for selecting a TI. Happy hunting to those who are investigating a new interface purchase. This is just one of a lot of good ones out there.
Here's some testing you may have seen that shows how a selection of interfaces stacked up against one another.
http://en.audiofanzine.com/external-audio-interface/focusrite/forte/editorial/reviews/be-forte.html