I mean at hero they definentally have a lot more utility options then either good or evil conjies. The draw back is that they are not excellent at anything really and controlling servitors can be a tad difficult to deal with.
The advantages are that you can switch between demons, angels, and archons and while you might not be able to conjure the strongest of them every time they should be predictable enough to control and you gain access to the utility offense of demons, the special abilities of the angels, and the healing of archons for when you need to tank.
Neutrals also have better luck with elementals I am told but elementals are cake.
Through use of the new edges a neutral conjie could even be rather proficient in either light or dark servitors and with the mastery over the one servitor type edge would be fairly close to a normal person of favorable align (eg. if you had master of archons edge you could use archons just about as well as a goodie would)
another thing to consider are the neutral familiars which I don't think have been given a chance to show their true shine.
Hidden advantage of neutrals might be that they do indeed have better elementals that can use elem commands more, if thats true it would be sick. Incinerate is so underused, yo gyuys realize it IMMOLATES people right, and earth elementals can make no exit rooms use these abilities people