I bought the Crown 7 Hydro last year and it was fine for a long time, but I've had issues with it.  The plus side is that I stopped smoking regular cigarettes altogether, and since I've been having trouble with my Hydro, I've been smoking almost none of that either.  I guess that's good, right? 
 
So my beef here is that while the system is really nice (good charger, nice, long-lasting batteries, easy to replace cartridges, etc.) I do have some small issues with it.  The biggest issue I have is that the cartridges I buy from Crown 7 brand new seem to be awesome.  They last quite a while, they have great throat hit, they have huge puffs of vapor, all that is dandy.  Then I go to refill them with a couple of different kinds of juice and they're absolutely terrible.  Poor throat hit, small vapor, many inhalations seem to just pull juice and don't vaporize properly, leading to sucking a big gush of juice into my mouth. 
 
So what gives?  I'm really not sure what I'm doing wrong here.  Should I get another model?  Is stuff like this normal? 
 
Thanks in advance!