I have not tried Atkins...and I ONLY like Slimfast Cappucino (tough one to find). I pick them up for $4.50-6 for 6-8 cans at
Walmart. I only use them so I can grab and go in the AM (15 min. of extra sleep...

) Try all the flavors...finding one you like is key.
Do realize that most people who use shakes for weight loss do NOT keep it off in the long run as they simply go back to old eating habits. There is nothing wrong w/ using the shakes to kick start your loss, but realize that you MUST make a dietary lifestyle change...FOR LIFE. (personally the shakes do not satisfy me & I am inclined to cheat)
I am following a lower carb lifestyle...I allow myself all the fruits, veggies, low-fat proteins (mostly poultry & seafood), and lowfat dairy that I would like. This is not limitless, but a small meal portion. I eat 3 small meals and 3 snacks of 100-200 calories. My grains are few (luckily they are NOT my favs anyway) and they MUST be whole grain...cereal (high fiber), ww pasta, 100% ww bread. It is my modification of the "no flour/no sugar" diet...BUT NOTHING is off limits, so that I don't feel deprived. I have lost 5 lbs in last 2 weeks this way. I did workout 3x the first week (Jazzercise...I have done it 3x/wk for last 5 years), but have been off last 10 days due to foot injury. But the weight still came off!

I have had a few beers the last 2 weeks...I did share a HUGE cookie yesterday w/ my mom at the farmer's market (where I loaded up on that fresh produce and some yummy lower fat goat cheese!)
I do feel eating 6 meals a day is key for me...I never hit a meal ravenous and overeat.
Since I have done this I did have one "free" day...I had mac & cheese and cinnamon rolls for lunch, and 2 small fried mini burritos/tacos for dinner (smothered in cheese)...needless to say my body revolted the next day! Certainly incentive NOT to do that again!
Good luck!