If I understand correctly, Infuse 5 is not a free upgrade. Is that correct? (I'm not complaining. I just want to make sure I don't buy it incorrectly. ;).
Assuming I'm right on the above point, I have a question about the $6.99 annual fee. Does this cover all future upgrades (e.g., 5->6, 6->7, etc)? If so, I think that's a good route to go - especially if the features added in each major version continue like they have in the past.