I'm trying Meyer lemon in my Old Fashioned tonight, and it's quite a nice combo of tart and mellow. I have been using mineolas frequently for OFs, but when I saw the Meyers at the market today I knew I had to use 'em. Instead of muddled sugar or simple syrup, I use blue agave syrup (and not much at that). And for bitters, I'm firmly in the Peychaud camp over Angostura, and I tend to dash in more than normal.

After making OFs with rye, bourbon/Tennessee whiskey and Canadian whiskey, I can tell you that rye is the winner...such a delicious spiciness with rye in the mix that I don't get with bourbon whiskey. Of those I've found, 90 proof Sazerac rye suits me best. The old reliable Old Overholt is just not interesting enough for me, and the Wild Turkey Rye tastes overproofed and, well, bourbon-like.

Finally, it's interesting to experiment with the OF style (without adding seltzer, or course). Have you tried using Tennessee whiskey as the spirit and muddled peach instead of citrus? OMG it's good sippin' I just love the venerable Old Fashioned style of taking "hard likker" (or "hahd likkah", depending on where you live ) to the next level.