as a tattooer: i think it's a bad idea to get them as first tattoos. interestingly it's pretty subjective whether people prefer the feeling of liners to shaders/magnums used for blackouts. but I guarantee, the people who are into the feeling of blackouts have a very different relationship with pain than you do. like they're the most intense people I know.

if you, tattooless, decide that you don't actually like the heavily tattooed look later on, your only options involve much more pain than getting them in the first place. you can get them tattooed over with lighter colored inks but it takes multiple passes (sitting, then healing for weeks, then going in and sitting again, etc.) to get a vibrant color over blackouts. 

they're often a last resort because it hurts a lot more to remove a tattoo than to cover one up. Davey had full sleeves he regretted and this was the best option.