Pros: Very good performer, well made, reasonably priced, includes carrying case, good warranty.
Cons: Doesn't cut as cleanly as top sets with higher tooth count
The 208 is an 8 inch stacked dado set that is sold as the SD208 Professional dado and the Diablo DD208 depending on where you purchase it. It includes (2) 8" 12-tooth outside cutters, (4) 8" x 1/8" 2-tooth chippers, (1) 8" x 1/16" 2-tooth chipper, shim stock, and a carrying caddy. The micrograin carbide teeth feature Freud-produced TiCO (titanium cobalt) carbide, said to maximize the cutting life and performance of the tool. Each chipper features an anti-kickback design. The set will produce dados from 1/4 to 13/16-inch in 1/16-inch increments. This set includes an instruction manual that offers guidance setting up various width cuts. The 208 is made in Italy and carries Freud's lifetime warranty.
The SD208 was my first "real" dado set. The first one I actually brought home was a lesser quality steel set that I insightfully exchanged for the upgraded Freud set after consulting some wiser veterans. The SD208 is a nicely made set with large teeth and a solid feel. The outside cutters feature an alternating top bevel grind (ATB) with a fairly low bevel angle. The inside chippers are flat ground (FTG). The "200" series is Freud's entry level for dado sets. The "500" series features similar quality but with twice as manyu teeth on both the outside cutters and inside chippers. They also offer a "600" set that features the same geometry and tooth configuration as the 500 series, but offers a unique adjustable "dial-a width" feature that makes changing widths much easier. All three are available in either a 6" or 8" version, and all have a 5/8" bore. The 8" has deeper cutting capacity, but the 6" is easier to spin for smaller saws. The teeth on 208 have a slightly negative hook angle to help make cleaner cuts. The downside of a negative hook angle is higher resistance, but fast cutting isn't typically a prerequisite for dado cuts.
In use the 208 performs well. The mild bevel of the outside cutters that's used to give a cleaner cut, protrudes just a bit higher than the flat ground chippers and leaves very slight "bat ears" at the outside of each groove. All dado sets I know of have a similar design and similar "bat ears". Even though many people report getting "perfectly flat" bottoms, that's not really an accurate description. The bottoms of dado cuts are flat aside from the tiny bat ears on each edge....look closely, the odds are good they exist. The cutters and chippers on the 208 are nearly exactly the same height to produce a nice linear bottomed groove. There can be minor traces of "striping" depending on the materials, but overall the cut will appear as essentially flat. Tearout levels tend to be higher with dado sets than single blades due to the shear width of the cuts, but tearout levels are well better than average and at acceptable levels with the 208. Using a backer board and a zero clearance insert can reduce the tendency for tearout. Overall the SD208 is a very good set for the money and is very popular with users. Wood Magazine rated it as a "Best Value" in a recent comparison behind the Forrest Dado King and Freud SD508 as top performers. If you need to achieve a cleaner cut than the 208 provides, you'd need to maintain the high level of quality and buy a set with more teeth. In most cases the price of the set increases significantly, and the improvement is minor. My DeWalt DW7670 set has twice the number of teeth and does leave a slightly cleaner cut in many applications, but it does cost a bit more on average, doesn't have an anti-kickback design, and the teeth are smaller and won't withstand as many resharpenings. My Systimatic Superfine dado set has 42-tooth cutters and 6-tooth chippers, and typically costs a small fortune (~ $250). As with many things, you need to determine what quality levels you need to achieve your objectives, and how much you're willing to pay for it. The SD208 offers what I consider good quality levels at a reasonable price. I don't suggest buying any lesser level of performance from a dado blade, and by all means avoid the "wobble" style dado blades!
A word of caution with dado cutters in general. Stacked dado sets achieve their flexibility in width by adding and removing the inside chippers and making fine adjustments using shims between the blades. The audible result of a large stack spinning at over 3000 rpms is a fairly loud throaty growl reminiscent of an airplane propeller. It can be a bit unnerving, which I view as a good thing. A stacked dado set is inherently more dangerous than the a regular single blade. The wider cut means more damage to any flesh that contacts the blades. There's a higher chance of mutilation as opposed to a clean amputation from a single blade. Installing a stacked dado often requires the removal of splitters and guards that are matched to a single blade. Extra care is required, and the sound of an airplane taking off from your saw should serve as a reminder to proceed with caution. Use featherboards, hold downs, zero clearance inserts, and push pads whenever possible. Think your cuts through, clear the surrounding area, and do practice cuts with manageable sized pieces.