Well, my point was that he is an artist as much as Spike is a hedonist (Angel/Angelus also likes to draw, enjoys watching ballet and apparently has collected artefacts from different parts of the world, so he found pleasure in more conventional types of art as well), but they are also both sadists. Getting pleasure out of snapping people's necks is as much sadism as enjoying the mental torture they feel when you're leaving them creepy messages and watching their reaction to having someone else's neck broken, it's just a different type of sadism. Spike quickly loses patience and he'd be too bored with it. Basically it's like the difference between a kid who gets a kick out of tearing off cat's legs and snapping its neck, and a kid who first tears off its leg, watches it for a while, pretends to give it a chance to run away, lets it wobble and try to run away and then catches it again and snaps its neck.

As for masochism, it's really common to have it go together with sadism (Marquis de Sade would've been more accurately considered a sadomasochist, though more on the sadistic side). Angelus was the one who thought of sticking his hand out in the sun to burn and taunting Spike to do the same.