Hey Nature,
I have a Van den hul Frog with the Extreme Tempest. Sounds fucking great. I also have a 'standard' Tempest - have not tried the Frog with the unit, I upgraded the other Tempest as part of the cart upgrade plan. My 'guess' is huge difference between the two Tempest models w/respect to analog. If you are considering a similar output cart, I could do an A/B between the units. Again, I am certain the Ex does a better job. Let me know - access to swap the units is not too bad.
Don