I bought these to put on my Charvel St Custom which is tuned to D standard/Drop C. I used to use 10-52 strings, but found that thy were a little light on the low end and the tuning would fluctuate when I played hard. With these 11-54 strings, the tuning is much more stable, even when I drop the 6th string down to low A. The tone is much better aswell, as it tends to be with a heavier guage.
Compared to the nickel-steel version of this set, the tone is a bit brighter, which is certainly useful considering that I am tuned quite low.
If you are looking for more brightness in a low tuning, you should give these a try.
The only negative is that they only last the same length of time as nickel-steel strings, which are about half he price.