A few months ago some friends and I teamed up to brew 15 gallons of IPA. Here's the recipe:
35 lbs. pale ale malt (80%)
4 lbs. carapils (10%)
4 lbs. caramalt (10%)
1 oz. Summit 17.6% 90 min
1 oz. Columbus 15.4% 60 min
1 oz. Summit 60 min
1 oz. Columbus 30 min
1 oz. Summit 30 min
3 oz. Columbus 15 min
3 oz. Cascade 5% 15 min, 10 min, 5 min, flameout
1.5 oz. Columbus 10 min, 5 min, flameout
We split the beer into 3 5-gallon batches and used a different yeast in each: one with Danstar Nottingham, one with Safale US-05, and one with White Labs California Ale. No starters or rehydration.
Bottled after four weeks in primary. We did a blind tasting three weeks later, and I was surprised at how differently the beers turned out. Here's a comparison:
Color: The Danstar and Safale beers turned out similar in color - both were golden yellow and somewhat cloudy. The White Labs beer was both darker - more of a golden orange - and more clear. White Labs wins on this dimension.
Aroma: Safale beer had almost no aroma at all. Nottingham had a faint citrus aroma. White Labs had a huge vanilla/caramel aroma. White Labs wins again.
Flavor/Mouthfeel: All three beers had an excellent creamy texture. The White Labs beer's flavor was dominated by caramel and vanilla, which pushed the hop bitterness and flavor to the background. The Safale beer, having minimal caramel/vanilla flavors, displayed more hop bitterness and citrusy hop flavor. The Nottingham beer was similar, but better - ample bitterness and loads of hop flavor. I love hops, so at this point in time I thought the Nottingham had the best flavor.
At the conclusion of this tasting session, I considered the Nottingham to be slightly better than the White Labs due to its superior hop flavor. A few weeks later, however, I performed another tasting session and found that the White Labs beer's vanilla/caramel flavors had faded somewhat, allowing the hops to show through and producing a more balanced beer. Now I'd say that the White Labs is slightly better than the Nottingham, but it's close to a toss-up.