Keep in mind this is all personal opinion, we all have different desires from our PVs. Some people will swear by their choice, but I'll try to be objective.
I've moved from claero's to carto-tanks. Cost is one thing, I prefer the "look". I need more than 1.6mL (1.4 really if you don't want a possible flood) of juice per fill. The juice thickening at 1/2 mark was a bit aggravating, I am on 100%VG and that meant I had to empty and clean quite often, maybe I could get away with a top up or two but that's about it. When I was using 50/50 I got a more mileage before this happened, but it still was enough of a problem that I looked at other options. Clearo's are definitely more "user friendly" from the get go.
If you've used a cartomizer then you know how a tank will perform, it just gets rid of the need to keep saturating the filler. They could have leaking problems (none here yet but watch:
A PBusardo Review - Smoktech Tanks - YouTube I love this video and use it often when discussing tank issues). Filling them is similar to clearos. Punching/slotting cartos can be a bother, leading to flooding and a useless carto. Torn o-rings and loose fittings are a potential problem. Depending on juice thickness primer puffs are needed, or you'll burn the filler. Baditude got it right, 90% user error (most PV issues tend to be from user I think, at least mine mostly have).
All in all, they have their ups n downs, the lot of em. I'd suggest picking up a decent tank and cartos. Brand of tank I can't really say, if it's sealed it will "work", smoketek, jtank, boge, there's plenty of reviews and videos to compare. Cartos, I'm using boge LR's, with 2 holes pre-punched and they're working just fine so far. Again, there's reviews everywhere so take a bit and see what the options are. I'm sure there's others who have more opinions, but keep in mind that a lot of it is opinion and personal.