04 - 06 Viper owners that have driven the GT just rave about it and the speed it builds above 120 mph. Where the Viper begins to wheeze the GT just keeps going.
The other thing you will find different is that the GT torque band is so flat and the HP so linear that it provides effortless power on hand in any rpm right up to red line. So much so that it’s a bit deceiving when driving the GT until you look at the speedometer or your lap times at a track. However the torque and power of the GT also make it a pleasure to drive on public roads.
The GT is also more comfortable, quiet, easier to shift and therefore a bit easier to drive than the Viper. Handling, brakes, overall power to weight - most will say the GT is a bit better, others may choose to disagree.
The level of interest about the GT is just way over the top. If you own a Viper, Corvette, Ferrari, etc you’ve already experienced this and know what I’m talking about. I don’t think any other in the US gathers this much interest. Stop for gas, a cold drink, etc and people just gather instantly around the car.
Overall I doubt you will find many people preferring the Viper over the GT.