I've got the Halycon and a bottom fed Sapor. It's a great bit of kit and well made. If I had to talk about negatives then the 900mah Lipo is a bit small. I have a 0.5 build and get a full day alternating between the Halycon and another mod.
I'm not over fond of the Sqounk bottle in the Halcyon, compared to the one in my Sunbox it's a bit small and I only really seem to get a good feed if it over half full, that said for the first time squonker it's a good bit of kit...
I haven't seen any yet - they're a pretty small size but I'll keep looking...