Allot of things will play havoc on attys:
- liquid viscosity is the biggest one;
- flavour;
- equipment used; and
- method used.
They were designed to be dripped, and although some have had some success with bottom feeders, were not designed with bottom feeders in mind. Bottom feeders have their own set of problems:
- if the pin is too long = will short out the atty if it come into contact with the coil. I have done this with others attys. I have also had attys that simply did not work on the device, but yet worked flawlessly on others;
- for feeders not using the pin, if the contact point is not totally sealed = may not be delivering the liquid to where it needs to go; and
- liquid viscosity.
There is a myriad of things that may or may not go wrong with an atomiser dependent on the aforementioned reasons. If individuals only have "A" device then I can see potential problems. OTOH before embarking on the next rainbow, folks should wait a little for some feedback? e.g. The first one I fired was the 1.8 stealth on the Omega with an 18650 = yuck! This was a live review during a conference call. I switched devices and moved it to my 3.7V boxmod =

Does that make it a bad atty, or one that needs to be vaped at lower current? OTOH the Omega is equipped with the 3.5Ohm for HV vaping.
Contrary to popular belief, one size does not fit all unfortunately and this can be seen with all the attys out there and not limited to the IKV line. Take for example the controversy with the CE2s, for the love of God I personally can't see why anyone would rave about them, but hey those who like 'em like 'em allot and I am cool with that.
In the case of the Cannons they do not perform like the 801 shortys. Why? They are not 801s. Do they have their place in someones vaping arsenal? I would say yes, they do in mine. Do I prefer them over the shortys? No. BUT that is not saying much because the variance is but one or two tenths of a point in favour of the 801s. 2 different atomisers for 2 different purposes. Once size does not fit all.
Hope this helps...
In closing one atty that never made it out of the blocks was the 306 tank, yet some folks rave about these, They are known and sold as mini tank systems, just goes to show you what some vendors know about the gear they sell. At less than 0.5ml capacity, that is not a tank!
Was Isaac disappointed when I showed him the pics of the LR 1.6 clearomizer that I scorched? You bet! OTOH reports were out there wrt this problem. The dual coil did not scorched perse but upon post mortem heavy discoloration of the sock was evident and scorching would have ensued sooner or later IMO. Folks do indeed rave about them, they are simply not for me and my vaping style (flavour). At 6V the DC provided a reckless TH, for folks that seek TH this puppy will get you there
I am also a realist when it comes to cartomisers. I do not expect them to last for weeks/months, it was never the intent in the design. It is something that was placed upon them from the over enthusiastic and demanding vaping community?