I really like the idea of the Possession traditions, and I like the way thte Possession power works, however I don't really care for the description of the Channeling metamagic technique, and I feel it could be expanded and clarified. In that aim, I'm considering the following houserule for may game:

Channeling (Option 1)
<<<flavor text as per Street Magic>>>
1. Physical Attributes are equal to the Magician's + (Force of Spirit)
2. Two sets of Mental and Special Attributes - one for the Magician and one for the Spirit. The combined entity uses the lower Mental or Special Attribute for any passive roll (such as resiting damage/effects or passing through an astral barrier).
3. The combined entity uses the lower Initiative with +1 IP over that of the unpossessed physical body.
4. The Magician uses his own Mental and/or Special Attributes when using his Skills and/or magical abilities. The Spirit uses its own Mental and/or Special Attributes when using its own Skills and/or Powers.
5. The Magician may only spend his Edge to aid his own actions (as above), and the Spirit may only spend its Edge to aid its own actions (as above). Either the Magician or the Spirit - but never both on the same roll - may spend Edge to aid a passive roll.

I have considered a 'flip-flop' that took a Simple Action to change from one controlling persona to another. This would look like this:

Channeling (Option 2)
<<<flavor text as per Street Magic>>>
1. Physical Attributes are equal to the Magician's + (Force of Spirit)
2. Two sets of Mental and Special Attributes - one for the Magician and one for the Spirit. The combined entity uses the Mental or Special Attributes of the dominant member (see below).
3. The combined entity uses the Initiative value of the dominant member (see below) and has +1 IP over that of the unpossessed physical body.
4. One of the components (Magician or Spirit) is the dominant member. This member is in control of the body and may use Skills and/or Powers as appropriate to them (the Magician may not access the Spirit's Skills and/or Powers, while the Spirit may not use the Magician's Skills or Spells). The non-dominant member is unable to act and is merely 'along for the ride' as normal for Possession (with the non-Spirit always being non-dominant). Changing member status from dominant to non-dominant takes a Standard Action.
5. The dominant memeber may use Edge for any purpose.

I'm still working on an Option 3...