These two ryes are ripe for comparison as they share a number of qualities in common: they are both aged for 6 years and bottled at 90 proof, as well as being sold at almost the same price.
Russell's Reserve Rye Whiskey
Neat, this whiskey has a bit of alcohol on the nose, as well as a slight tinge of vanilla and a very robust amount of raw or toasted grains. The smell tickles the nose, promising that rye spiciness that is a hallmark of the spirit. The taste is made up primarily of the aforementioned grains, with a burst of chile pepper on the swallow. The spicy burn tends to linger, though in a not entirely unpleasant fashion.
A couple of drops of water subdue the smell and flavor to a degree, bringing it a little bit closer to bourbon territory without giving up its distinctiveness. The back of the mouth spiciness is, however, completely undiminished.
With all that said, I feel like this is a fairly simple rye. 90% of what's going on is either hot spiciness or rounded, somewhat mellow graininess. With time in the glass, the balance shifts a bit towards the grains and it calms down a smidgen to reveal some of the corn in the mash bill, but you're still left with pretty much the same drink.
In cocktails, I feel like Russell's Reserve Rye is a bit disappointing. It lacks the robustness of Rittenhouse and doesn't stand up for itself nearly as well in a basic whiskey sour. A small dash of bitters can mostly rescue the drink, but given that this is also more expensive that the Rittenhouse, I feel like it's hard to make a really compelling case for Russell's other than in terms of availability. However, if you give this one a try and like it, I'd also suggest trying the Russell's Reserve 10 Year Bourbon. There's a clear family link between the two and it still has a fair bit of rye character while being balanced by a higher proportion of corn.
Sazerac 6 Year Old Rye Whiskey
Produced by the Sazerac Company of Sazerac cocktail fame. While only administration of the company is still carried out in New Orleans, the association with the birthplace of the company is still strong. Distilling of the company's spirits is done by Buffalo Trace Distillery in Kentucky. Known primarily for their bourbons, there are a number of different ryes that are now being put out as well.
Sazerac rye has a slightly different mash bill than the Russell's above, being composed of 51% rye, 12% malted barley and 37% corn. The difference is readily apparent as this rye is much less aggressive. The nose is mellower, while retaining a slight prickle from the rye spiciness and whiff of alcohol. A bit more vanilla and a touch of fruit are added to the mix. The higher proportion of corn is also evident in the taste, which has more corn sweetness with a less explosive spiciness and less of the straight grain flavor of the Russell's. A couple of drops of water turn down the dial just a bit without washing out any of the flavors.
I feel like this is a really good rye for bourbon drinkers. While all of the requisite rye characteristics are present, there is enough bourbon character underneath to provide something familiar as well.
Right now, I'd still have to recommend Rittenhouse over either of these ryes. It's cheaper and has a depth than neither of them can match. However, it's also kind of tough to find, so in a pinch I'd go for the Sazerac. It's much more balanced and has a bit more depth. The Russell's could actually be a pretty good rye if it just mellowed a bit and got some more complexity. If we're lucky, Wild Turkey will decide to put out an older version in the future. I have a feeling that with some more maturity it would end up being a pretty good whiskey.