I like the idea of magic because you can play a lot of it in public spaces. You cannot have a sword fight on the main street on a friday night unless you want to have a visit from her majesties constabulary.
While magic would be extant in the world, it would be fairly restricted in use. If you were playing a Witch ala Charmed you would start with a power and a heavy energy drain. Besides their power most of their spells were quite fixed. I.e. they needed circles or a potion. This limits the use of these spells.
Dresden is a good example of magic in the game. Avialable, but don’t let the plebs see to much.
Cthulhu traditionally has magic, but you risk your sanity using it.
Buffy had magic, i.e. Willow, but no character will be acting like black vein Willow, rather again the use of circles and talismans and the occasional zappy use.
Things like a Proton Pack for a Ghostbusting team would act as a magic power.
If you don’t have magic then you do not capture the spirit of the genre, but to much magic can get out of hand. Not all players should have magic, but those that use magic should have their own weaknesses so that they have to be a part of a team. and if you are facing a supernatural threat I am sorry but a SPAS 12 just ain’t going to cut it. You don’t lead, you need magic.
The idea of a game like this is that you actually play it in city on Friday nights, like the Masquerade is meant to be played. And occasionally you have a fixed piece encounter when you pull out the Nerf guns and the Super Saturators and kick some super natural butt.