An atomizer is more versatile, you can use a cartridge, or drip. Supposedly they last longer, but I guess YMMV. I've been using the new edition 5 CE2 clearomizers, not totally unproblematic, but much better than previous editions. I haven't killed one yet, but I also haven't killed any attys yet either, so I can't say which will last longer. But, even if the clearos last 1/5 as long... they are 1/5 the price. I've never cared much for cartomizers or carts, and dripping is too much hassle. Clearos give me the same flavor as dripping, but less hassle as a fill lasts so much longer. You also know how much liquid you have left in a clearo, vs. a carto, and very little is wasted.
They are very different designs, but it would seem that unless an atty lasts much longer due to being higher quality, either a clearo or a carto should cost more, not less, they have more parts than an atty.
I'd like to see a sixth revision clearo, maybe dual coils, and certainly using the same tubing as a 3ml syringe, out of the box and not having to modify them.