First off, I need to state that the picture of this product is incorrect. The image they erroneously used is Chef's Choice 4 (by EdgeCraft) and is priced considerably higher. As far as I know, BestBuy does not carry this model.
The unit you do get is the one detailed in the product info, the Presto EverSharp Model# 08800. It features a two-stage system as any decent sharpener does. The first grinds the blade on both sides, and the second hones and polishes the blade to a fine edge.
If you're new to sharpening your knives, it will take a little getting used to. You need to keep in mind that all sharpening will reduce the blade so don't be surprised to hear the sound of metal grinding away and a ever so slightly thinner blade at the outset. The unit is super easy to operate, there's only one on/off switch at the front of the unit. The slots are angled optimally so there's no skill required on your part, all you need to do is draw the knife through the slots.
I had to use several passes as my knives were quite dull, but they came out noticeably sharper. From a functional perspective, the Presto is a great entry level set for the home cook. It's priced right retailing for about $30, easy to use, and requires little no cleaning (you may have to empty out some metal filings after some extended use, but that's easy enough as there are two receptacles underneath).
The design is ok. It has suction cups to help secure the unit to the counter, but they could have done a better job with the power cord in my opinion. The power cord is fixed to the center on the back side of the unit. The power cord measures 32" long (not including the plug). If you don't have the cord fully extended the 32", it may "bunch" up, and if you're not careful, your sharp knife may slice through it as you're pulling it through the slots. A better design would be two-fold, 1) do not fix the cord, have an outlet and a removable cord. 2) position the outlet from either the side of the unit, or the back corner so that it's out of the way. Despite these pitfalls, the unit itself functions well for an entry level sharpener which is why I'm giving it 5 stars.
Note: This machine is suitable for knives made of alloy, carbon, or stainless steel. Knives that have a high carbon content will spark, so don't be alarmed if you see some flying. This machine is NOT suitable for serrated blades, but I suppose, if they're only serrated on one side, you can sharpen the flat side.