I recently got into scotch. I've yet to try any campbeltown single malts. How do they compare to speyside, highland, or islay? So far, my favorite is glendronach 18.
Scotch is generally split into 3 basic flavor categories:
Non Sherried
Sherried
Peated
Sherried scotch has been matured in ex bourbon casks and then further matured or finished in olorosso sherry casks. The best example would be Macallan, Glendronach along with countless others.
Non Sherried scotch is well...exactly like it sounds. The spirit is matured in ex bourbon casks just like most other scotch but it isn't partially matured or finished in sherry casks. Glenmorangie, Balvenie, Dalwhinnie, etc..
Then you have peated scotch where the peat has been used to dry the malted barley and this instills the characteristic (love or hate) brine, smoke, peat characteristics. Peated scotch is high in phenols and the phenol concentration in PPM can sometimes be used to further describe the level of smokiness. Lagavulin, Ardbeg, Laphroaig, etc..
Almost all of these three basic types can be found in all "5" scotch whisky regions. However, the vast majority of peated whisky hails from the island of Islay where peat is in abundance.
The five whisky regions are as follows and I would say that splitting them up into "regional" scotches doesn't necessarily correlate with specific flavor profiles or aromas. It's really dependent on the distillery. However, there are a few basic qualities that can be applied.
Speyside - Very little peat if any at all. Flavors are fruity with an abundance of apples, pear, honey, spice notes and many of them are finished in sherry casks.
Lowland - Lighter bodied whisky. Floral, honeysuckle, toffee, some spice, grass, etc..
Highland - Very diverse, difficult to characterize and dependent on the individual distillery.
Campbeltown - Slightly heavier bodied compared to Lowland. Some distilleries lightly peat their whisky. Toffee, fruit, vanilla, touch of brine and smoke, etc..
Islay - Heavily peated whisky. Salt, brine, seaweed, asphalt tar, licorice, plumes of smoke, etc..
Instead of buying a specific region and judging it based on the region, I'd buy a whisky based on the first three flavor categories and forget about the region. Instead, focus on the distillery.
If you're a bourbon drinker, I generally always suggest Balvenie Caribbean cask as a first single malt for bourbon drinkers. It's fruity, not too complex, smooth, with lots of honey, toffee, etc.. The flavor profile is not too dissimilar to many bourbons and I have yet to find a bourbon fan that didn't enjoy the bottle.
I generally don't buy 18y scotch anymore. Its very difficult for me to tell the difference between a 15y and a 18y and I'm somewhat of a scotch nerd and have a fairly refined palate at this point. I can easily tell between a 12 and 15 but I really have to concentrate to tell a 15y from 18y and can't do it reliably. The price difference is so great between 15 and 18 that I don't find it worth the extra $$$ unless it's a special bottle that I want for other reasons.