My VE300 is set at 94 for my rack. It makes a hotspot of 90-91 over the flexwatt and 78-81 ambient so far in the rest of the tub (depending on time of day and amount of sunlight coming in the nearby window).

The t-stat probe is taped with foil tape directly to the flexwatt and the temps inside the tubs are measured with an Accurite and confirmed with a temp gun.

I'm still studying this though - the rack is brand new. I'm a little concerned about the ambient temps getting too high because it is near the window which lets in a lot of light. Might have to move it. And I might have to raise the t-stat setting a smidgen once I add the substrate. We'll see....