Overall are any of the Agilent PC based scopes usable as a every day scope?
I'd say, yes, they are. Agilent makes good scopes, and their Windows scopes are no exception.
What I dislike with Agilent however is their GUI, which is based on the old mouse-driven UI from the old first generation Infiniium 54800 Series of Windows scopes. They added touch to it but it's not really optimized for touch, and clearly feels like a standard mouse UI. I very much prefer the MAUI interface LeCroy has put on their scopes, which has been designed for touch from the start. It's still by far the best scope UI I have seen on any Windows scope.
The other thing is that Agilent seems to have difficulties getting good performance out of their Windows architecture scopes, which shows amongst others in the pretty low waveform rate. Their non-Windows scopes since the old 54600 Series are almost all pretty fast (albeit very limited in functionality), but the Windows scopes seem to have difficulty catching up to LeCroy's X-Stream scopes (which are Windows scopes), which in general seem to perform much better under comparable situations.
As I said before, the DSO9kH isn't a bad scope, but because it was essentially a "me, too" product from Agilent when LeCroy came out with their true 12bit scopes (HDO Series, WaveRunner HD) it lacks optimization in several areas.
If you want Agilent and don't need 12bit then maybe the normal DSO9k might be an alternative if it fits your budget. It's waveform rate is still pretty low, but still faster as for the DSO9kH. I'd also recommend to stay away from the older Infiniiums with the smaller 8.4" screen (i.e. 54800, 8000 and 80000 Series) as their waveform rate is abysmally low.