Clearomizers are primarily "tanks" or delivery devices which rely in most part to negative pressure within the tank to work correctly. The same principle of negative pressure is used in cartotanks, too, which use a different kind of wicking system. Clearos use silica string wicks, cartos use polyfill fiber.
I don't use cartomizers solo; I only use them in cartotanks. But a carto used solo shouldn't have the pressure issues that they might have when used in a tank. You may find better flavor production in a cartomizer than a clearomizer. But their main drawback is since they are stainless steel tubes, you can not see the juice level to know if they are getting low on juice, possibly burning the filler and getting a burnt taste. Having said that, carrying mutiple filled cartomizers or bringing your juice bottle with you for easy top offs might solve your problem.
There is a difference in the filler material in cartotmizer brands. Boge's filler is more densely packed, making filling them with juice more time consuming depending upon the method used filling them. Smoktech's filler is less densely packed, making filling them easier and faster, but some people find that they are easier to flood.
As I stated, I only use pre-punched cartomizers for my cartotanks. I have a list of vendors that sell these in the below link. Once on the website, you can redirect your search for un-punched cartomizers.
http://www.e-cigarette-forum.com/fo...nched-single-coil-cartomizers-cartotanks.html
You might consider one of the following cartomizers to try. There are clear cartomizers which would allow you to see your juice levels as you vape; be careful of the flavors that you use in these as I'm not sure if they can use those flavors known to crack polycarbonate plastic. There are also the XXXL size cartomizers which hold nearly 5 ml of juice.
AltSmoke.com - 510 Dual Coil Cartomizer
http://www.e-cigarette-forum.com/forum/blogs/baditude/3733-6-something-safe-cinnamon-citrus-flavors.html