The touch-screen interface on the Exhibit, like on other Android powered handsets, is easy to learn, use and master. People of all ages can quickly understand how the system works as it is all touch based. Samsung also included a very simplified version of TouchWiz on top, which provides consistency with the rest of the Samsung line up. It would have been preferrable if Samsung just went with stock Android, but TouchWiz isn't too intrusive and does give the phone an iOS feel, so it evens out.
Using the keyboard in portrait mode does take a bit of getting used to due to the smaller screen and landscape will most likely be your preferred usage of the virtual keyboard. The responsiveness of the touch screen is decent and therefore typing on the Exhibit 4G feels natural, even though it's a virtual keyboard.
The Exhibit 4G also comes with T-Mobile specific applications to enhance the user experience. Some of the T-Mobile specific applications include T-Mobile AppPack, T-Mobile Highlight, T-Mobile Mall, T-Mobile Name ID, T-Mobile TV, and Visual Voicemail. T-Mobile has gone all out in adding these extra incentives and it's refreshing to see something like Visual Voicemail consistently being offered for free, which isn't the case with AT&T, the company buying them out.