Sous vide not only keeps the proteins (main component) at a lower temperature, but also the spices/oils/flavorings. Heat helps release the taste and aroma of all the ingredients, and the sous vide might not be hot enough to do that.
So, while it kind of kills the simplicity, you could always sautee the seasonings in oil before adding them to the sous vide bag (not until cooler though). Or just keep them separate and recombine for serving. Sous vide itself (not the vacuum part) is mainly for maintaining/achieving a controlled internal temperature, and skilled cooks don't only sous vide a dish; they might sous vide and then finish under a broiler for texture, or with a torch. If the sauce isn't working inside the bag, make it work outside the bag.
Alternately, put the ingredients in the bag the day before, and let them marinate overnight in the fridge. The vacuum action is essentially just a speeded up marinade, so this should do the same.
Also, make sure you're using enough (but not too much) SALT.
Finally, call the Sous Vide Supreme company. They know their product's capabilities and limitations and might have some good recommendations.
Just my guesses.
The advantage would be cutting some sodium out of your diet. If you are like many in the western part of the world, you probably get more than your daily allotment of sodium regularly. By making sure to cut sodium where you can, you gain the health benefits of a well-balanced diet.
Since salt is a flavor enhancer, a low-sodium diet can often seem bland. Many look for alternatives. Vinegar brings out flavors in a different way and adds a significant flavor of its own. I'd start small, using just a bit of vinegar.
Best Answer
If you want to give something the flavor of almonds, then starting with almonds, in my opinion, is superior to starting with the cousin of almonds. Of course, if your persipan is, in your opinion, indistinguishable from marzipan, then go ahead and use it in good health, but it is likely that it has added flavors to get it to that point (natural or otherwise, depending on manufacturer).
Modern, sweet, cultivated almonds have a stronger almond-y (and in my opinion, better) flavor than apricot kernels and, I would presume, peach kernels (I haven't eaten those).
Almonds, peaches and apricots are close relatives and the kernels are generally quite similar. Most peach and apricot kernels (as well as bitter almonds) are not edible in their fresh, raw state because they contain cyanide in the form of amygdalin. There are actually some apricots with kernels that are edible without extra processing and in my experience, they aren't as flavorful as almonds, although I guess there could be some varieties with more flavorful kernels, but I think the ones that are being used for the persipan are more likely to be leftover from fruit production and not a specific variety bred for the kernel itself.
When you make marzipan, you just need to grind up blanched almonds. When you make persipan, you need to process the kernels to remove toxic chemicals, which removes much of the bitterness, and then grind them up and probably add in some flavoring.
I expect it is possible to get the persipan to approximate the flavor of marzipan, and I would expect the texture to be about right to begin with, but personally, I would say that yes, making marzipan from almonds is superior. It's using the variant of that particular nut-bearing tree that was bred throughout the centuries to make the flavor that this food item is most expected to highlight. Marzipan IS almond. ...and sugar, sure, fine, whatever. ;-)