Generally speaking, I think Samuel Smith’s beers are pretty fundamental, maybe essential, beers that should be considered benchmarks. Taddy Porter is like that for English style Porters, I think. Or very nearly. Basically, it’s one of the best English Porters out there.
Appearance: Dark brown and opaque, like dirty engine oil. Poured a nice foamy head, chocolate tan in color.
Smell: Coffee, chocolate malt. Nice roasted grains. Rich and deep. Fundamental; there’s something about these good English ales which are, to me, fundamental to beer—in this case, it’s the aroma you expect when you think "Porter." (Kind of archetypal, I guess.)
Taste: Complex interplay of dark malts, roasty coffee flavors, chocolate (bittersweet), slight lactic sour note, dry. The dryness comes from the roasted malts, with a hint of charcoal.
Mouthfeel: Creamy, smooth, almost oily rolling feel in the mouth. Nice medium body, not chewy but close.