It's something you just have to try. The two givens are that you'll get a different flavor profile than with a hot infusion, and a different flavor profile than with infusion into water (the fat in the cream is a much stronger solvent for a whole range of flavor chemicals).
Some of the differences have less to do with temperature than with the fact that cold infusion is usually done in a sealed container, so the aromatics don't get out. Hot infusions in a saucepan usually involve container open (or partially open) to the air, and temperature-induced evaporation. But this doesn't happen if you infuse sous-vide — sealed in a bag, those aromatics aren't going anywhere. The trick here is is to hot-infuse at a temperature that's not too hot, and then to chill the bag in an ice water bath before opening it (the latter step makes big difference if the cream will be used cold; less of a difference if you're going to cook it later in an open container).
Sometimes hot infusion by sous-vide is too much ... you hold on to more aromatics than you want. The times i've put garlic in an s.v. bag I've regretted it.
Edited: I wrote that fat is a stronger flavor for the aromatic chemicals, but I don't think this is right. Those are water-soluble. The fat-soluble ones are heavier molecules that we taste on the tongue.
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