Have been vaping both of these atties for quite a long time. (About 2 years or so) My Hadaly has been in more consistent use owing to it being single coil (easier to maintain) and me using it quite often to test out new flavours. (less admin to change a single wick) My Petri V2 RDA has been out of action for a month or two. Only got it going again today. I use it occasionally in the evenings for a bit of fun and more clouds. Not a workhorse vape for me. So I thought I would vape them side by side and just summarise my thoughts - and see if we have a winner. Short answer is they are both fantastic and there is no clear winner for me. They both give an outstanding vape and I love them both! They are very different though - the Hadaly is a tamer single coil vape while the Petri V2 is a more intense (but not crazy) dual coil vape. Here are my thoughts: Draw Both are DL but the Hadaly's draw is quite a bit more restricted. The Hadaly is a perfect restricted DL for me. You can feel the restriction. The Petri V2 is a lot more open but not too airy at all. Most would probably also say its a restricted DL - but its less restricted. Flavour Both are outstanding. The Hadaly's flavour is a bit sharper and given the tighter draw, it does feel more concentrated. Lovely. It produces very accurate flavour for me. The Petri also has outstanding flavour. Despite more airflow, the dual coils help and produce a lovely rich flavour. It's slightly less concentrated and I find its slightly wetter and "juicier". Hard to call a winner on flavour. They are different but both very good. Accuracy on the Hadaly versus a bit more of an intense vape on the Petri. Ease of use I use them both as drippers, not for squonking. They both work well and haven't given me a problem. The Hadaly can leak out the airholes if you drip too much but you get to know how many drops to drip for a lovely saturated few vapes without any leaks. I had to remove the top o-ring on the Hadaly to make the cap a bit looser. The stock setup with both o-rings leads to the cap being too tight for me and it makes it very hard to take it off. The Petri is easy to use. Both are simple to build on. On driptips, I had to change the driptip on the Hadaly. The stock tip was too small and I found my lips resting often on the actual atty. So I am using the Merlin Mini tip, which is one of the most comfortable tips I have used. Doesnt look good on the Hadaly but I dont care about that. The Petri's stock tip is perfect for that atty. Overall I can't say I prefer one to the other. The vapes are different though. The Petri being dual produces much more vapour and its a more intense vape - around 60 Watts. The Hadaly is a bit more subdued in comparison - more of a mellow kind of vape. But has great accurate flavour. Both are fantastic and I will most likely continue using them for a long time to come.