I moved on from clearos fairly quickly. They've always been troublesome to me. Either something was leaking, or it was gurgling, or it was burnt out. The issues would pop up at the wrong time too. I have a two hour commute, and I don't have the time to do much troubleshooting on the road. I'm into Kayfun style tanks now for the most part, but I was very happy with cartotanks as well. I would have stayed with cartotanks indefinately if I wasn't worried about FDA regulations and the taxation that's sure to come. I think that cartotanks are the least problematic toppers around unless you want to go into rebuilding.
I got my cartotanks from IBTanked. Pricier then Smok tanks, but not as pricey as Phiniac. All in all, I think they're the best combo of quality and price around. Nice, thick, glass tubes with metal endcaps. No need to worry about juice reacting with anything. I use Smok, single coil, cartos in them with two laser punched holes. Boge gives slightly better taste, but the filler in them is far more dense then Smok, and they take forever to prime. The Smok cartos lasted longer for me as well. Surevapes has bulk deals on Boge, and IBTanked has Smok for a good price. Single coil cartos can be cheaper then many of the dual coil heads for clearos if you know where to look.
Once a carto is primed and inserted into the tank, and the tank is filled, the cartos last quite a while. No dry burning between tank fills. Just top off the tank until the carto dies, and they die long, slow deaths. You'll get plenty of warning before one goes. I could usually run around 30ml of e-liquid before it's time to change one. It initially takes a bit longer to set it up due to priming the carto (drip juice until the filling can't hold anymore), but all in all they took up less of my time because there was less troubleshooting involved. Taste was also better to me than any dual coil clearo I've tried.