Picture quality in most ways equals laser disc video, and copies from one S-VHS tape to another are outstanding. Up-front jacks for the input and output cables. They make copying to and from another VCR or a camcorder much easier. A jog shuttle. It lets you zero in on a single video frame easily.
Features vary, but in many cases digital circuits can improve the picture and sound.
Finally, there are a few features you can safely avoid. One is a mid-mount tape transport, which is supposed to make for a better picture by keeping vibration at the center of the VCR's chassis. I haven't seen any proof that this works. The resulting videos don't look any better.