I´m one of them... I´m satisfied with my 3DS the way it is and I don´t feel the need of bigger screens, since i play it mostly while communting or during my lunch break... but some people may want it so it´s great for consumers to have an option
As for the second analog slider, i´ve been playing Kid Icarus and Resident Evil Revelations and it´s pretty easy to play them without the second slider - no hurting at all, but some people say that I have long fingers and that helps holding the device with only one hand and the stylus with the other....
The only game I feel a bit of difficulty to play using the buttons was Metal Gear Solid Snake Eater, it´s kind of cluncky to control the camera using the buttons, but I really felt that this was also a problem of game design. Had Konami used the touchscreen for camera controls and it would be much better.
Regarding this we are in a two-way lane here: It would be nice to Nintendo to launch this revision with the second slider, but it would be mandatory for developers to design their games ALWAYS with the original design in mind, and the option to use the second slider, that could require some more programming.... on the other side, owners of the previous editions would feel that they wouldn´t be able to full experience the games just because those wont be designed for them.... in the end, I believe that it´s a wise decision not to include the second slider. What we´ve seen so far shows that it´s just a matter of game design - we can have and play great games without it.