All three are excellent. Which is more aesthetically pleasing is one of the primary differentiating factors. The Triade uses 3 18650 batteries which makes keeping a full charge easy by rotating out to an external charger. The pentagonal shaped enclosure is comfortable in the hand (like an RX200). The Efusion Duo offers 200W with the 3S Lipo, or 133W with a 2 slot 18650 sled, again making it easier if you prefer an option of Lipo or 18650. It's certainly more boxlike, resembling the Lavabox more in that sense, although without all the extra little angles and edges.The Lavabox uses a replaceable Lipo, with 900 or 1300 mAh options. You are therefore limited to onboard charging only (same with Efusion in Lipo configuration).
Comes down to your money, your choice. I have a Triade and an Efusion Duo, and am happy with both. I doubt you will go wrong with any of those choices.