Wow, there are many ways to answer this question, but in the end it all boils down to your sensitivity and the type of riding you plan to do.
First off, since both the solid Tahoe and the suspended Tahoe GT both have fat tires, you will be able to air them down to have a smoother ride. To a point. Depending on your weight combined with the weight of anything you might be carrying on the bike, going too low on tire pressure can result in pinch flats. And running lower air pressures means more rolling resistance, and fewer miles per battery charge (or more pedal effort on your part).
The classic Tahoe is rated at a lower top speed as compared to the Tahoe GT. As such, not having suspension will not be as big an issue.
The Tahoe GT is rated at 28 mph top speed, where suspension can really be beneficial. And it has not only the suspension fork, but also a suspension seat post. Generally looks to be a nice and comfortable set-up.
The swept-back bars on these bikes will also contribute to a more comfortable ride, especially on the Classic Tahoe. They provide a laid-back riding position, where your weight is mostly on your butt and not leaning down on the bars (as would be the case of a more forward or agressive riding position on, say, a commuter bike with flat bars). With the laid-back riding position you won't feel the hits your front wheel takes so hard through your wrists up into your shoulders.
So the Tahoe GT is about $700 more based on MSRP. It gives you not only a suspension fork, but also a suspension seat post. Also a higher powered motor, a larger capacity battery and a higher top speed. It seems that if you are going to need your bike to get somewhere then the extra $700 being asked is justified for the upgrades. If you are just wanting a bike to cruise around the neighborhood, the bike trail at the beach or lake, etc., then that extra $700 might not be of value to you.
One thing I can say is that if you think you will want or need the suspension fork (and seat post), get the GT now. Don't think to yourself that you will just get the less expensive bike and try it out, and if you don't like it you can upgrade it later. Will generally be more expensive in the long run and less effective.
Buy once, cry once?
Good luck in your choice.