The only horror story I've heard about the kits that use a liquid is that they don't remove as much material as they should. However, the Skip Dr. is not without flaws. It resurfaces great (although no resurfacing will save you from deep scratches or label-side damage), but it leaves the plastic streaky. It shouldn't hurt readability much, and it will probably work fine. At any rate its way better than scratches. Anyway, if you don't like the appearance of a Dr. resurfaced disc, you can use one of the liquid kits AFTER to remove that swirly appearance. That's probably the best combo, use the Skip Dr. to do the grunt work and then the liquid solution to polish it up.
Or you could just take it someplace and have them resurface it.