Higher magnification is definitely NOT always better. Indeed, the microscope you are considering is designed for maximum magnification of 1,000x. The 2,000x is achieved by adding 20x eyepieces BUT it creates what is known as 'false magnification'. 2,000x is beyond the resolving power of a light microscope so what happens is that the image is magnified 2,000x but without a corresponding improvement in resolution. In fact, you will notice a degradation in image quality....it's like magnifying a pdf on your computer....it gets bigger but you still can't read it! And in any event, you will never use 2,000x let alone 1,000x! Read this article http://www.microscope.com/education-center/articles/false-magnification/
Second, I advise against buying an integrated digital microscope. Far better to buy a standard trinocular microscope and add a microscope camera. The reason is that the camera will be obsolete within about one year while the microscope should last a lifetime. If anything goes wrong with he camera, you will have to buy an entirely new microscope. Moreover, with separate scope/camera, you can switch cameras on the same microscope or use the camera on a different microscope. For more info read this article http://www.microscope.com/education-center/articles/digital-microscope-options/
Look for a lifetime warranty. A mechanical stage is standard and helps move the slides on the stage.
In full disclosure, I own www.microscope.com so give me a call if you would like any further assistance. You will not find false magnification or false advertising on our website!