How do I impart "extra" flavor with Sous Vide cooking? I've been cooking Sous Vide 2-3 times a week for about 10 months now, and I absolutely love it. The control of temperature and time makes for some really interesting possibilities. But, one of the touted benefits of the method is better imparting of flavors during the cooking process, and I'm not getting this at all. 

I'm not using a vacuum sealer in my process, instead I'm submerging an open bag in water and letting the partial pressure get all the air out before closing it up. Is this the reason I'm not noticing the additional flavor? Do the muscles in the meat need to be stretched by the vacuum? If that is the case, is a home vacuum sealer sufficient for that? I somehow doubt that a vacuum sealer gets much more negative pressure on the meat than my method. Do I need a chamber vacuum to get the effect?

Or am I just not using the right ingredients in my recipes? 

What am I doing wrong? I love my Sous Vide Supreme, but I feel like I'm missing out on a piece of the experience. 

Edit: 
I tried looking for some of the recipes that I haven't had luck with last night, but because everything is mostly google searches, I couldn't really come up with anything concrete. However some things that haven't really added that extra flavor are: Olive oil, butter, bacon fat, rosemary, thyme, and garlic. Not all at the same time, but in different combinations. A lot of my initial reading was careful to point out that you shouldn't use too much seasoning as the tastes would be much stronger than you were used to. I'm not getting that at all.
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.