Mesh - I use the Line 6 KB-37 as my primary audio interface when tracking / recording vocals and guitars.
True, with the launch of Windows 10 there was a lag to get the drivers caught up, but Line 6 came through and the drivers are working now.
There's a very prominent reason I use the Line 6 for my vocals / guitar tracking over my Focusrite audio interfaces (which I use for everything else including mixing). I get a far superior low latency experience with the TonePort (kB-37).
I would not call their drivers flaky.
I have had success with PodFarm 2 with my Focusrite as the audio interface, and the KB-37 is connected by USB. It's like a dongle in that case. PodFarm works fine that way as well. But for my setup, the latency is with the Focusrite lags in comparison.
Actually, with all that said, even though I get great sounds out of PodFarm 2, I switched to using Amplitube all the time. I just prefer it. But I still use the KB-37 as the audio interface for Amplitube because of the essentially zero latency performance.
Mesh, Sonar allows us to easily switch between audio interfaces. So I freely use both the Line 6 and the Focusrite for different tasks.