I bought a Krome and tend to use it more than my HP.CPlus or Talon, has a nice feel about it, I guess the Spirit would be similar. Keep in mind its .21 needle, can be fun with metallic's and maybe metalizer as I'm about to find out.
Here's a site which may help:
sites.google.com/.../home
or
users.tpg.com.au/.../airbrushpage.html
Good luck Dave,
Cheers from Mick.