I love Drop-C tuning, and this strings set have been always my choice. From 1 step down to Drop-C, never had problems using it, and it always sound great! Nice feel, good response and never going out of tune.
Strings should only be used if the player is planning on playing on Eb tuning or lower. These are not to be fiddled with at all. Great for a very deep (almost baritone) sound for a guitar, but not something I would consider strumming.
The Ernie Ball not even slinky is a great guitar strings, its comfortable, heavy, but my strings got rusty in a short time so that's kinda makes me sad about this strings, but they're still good and and its nice to play it.
So these strings are strings I use for my Ibanez. For a much heavier tone, and a much richer tone. If you want to drop-tune your guitar to anything, these are the strings to get. Because if you use a lighter gauge, the strings will get really f**ked up and the tension will be weird and it'll ultimately screw up your neck to the point where you would need a professional to fix it.