I want to clear up a bit of misinformation here.
First off, according to Aspire, these are the recommended wattage ranges for their Atlantis coils.
5.ohm = 20W-30W
1ohm = 40W-50W
.3ohm = 70W-80W
NOTE: The 1ohm coil is rated for higher wattage than the .5ohm coil.
Now, the next question is just how fast are you going through a coil? A day, a week, a month? And how many ml of juice do you normally run through it a day? For example, if you're only running 5-6ml of juice through the coil in a day and the coil is failing in 2-3 days that may be a problem. However, if you're running 10ml of juice through the coil per day and the coil is lasting 10 days then that would probably be considered normal.
And finally, there is the juice itself. The juice makes a HUGE difference on how long a coil will last. Thicker juices, darker colorings, and lots of sweetener will all contribute to gunking up the wick and coil faster. Clear juices with little to no sweetener can make a coil last a LOT longer, often times more than double the life of a dark, thick, sweet juice. For example, you may only get a week or so use out of a coil if you're vaping a near-black sweet chocolate flavor while the same coil may last a month or more with a clear, uncolored and unsweetened peppermint. Also the amount of vegetable glycerine (VG) makes a difference as well. VG is very thick and hard to wick, so you may get more dry hits and burnt taste from a 90+% VG juice than you would a 70-80% VG juice. Personally with the Atlantis I would recommend staying in the 70-80% VG range.