Well you only just got your 3, that is debatable, how much are you liking it?? The 2 is a bit tamer, more forgiving holding down the button, may need a little preheat, maybe more consistent performance fresh to low battery?? Since you are always holding the button longer there generally...
The form factor is different, the Milaana II is the smallest, taller than the 3 yet thinner on all sides, but fully rectangular without rounded side opposite the button... They have air intake in the same place like the 3 however it is a slightly different size hole, they also use mica insulator plate between the fold in the steel mesh heater instead of the ceramic insulator plate that the 3 uses (which is the same as the V Splinters nearly all made in China) and there are many other parts and material differences between the 2 and the 3 (like bronze or brass for the battery hatch plate) so all of this can lead to subtle differences in the vapor quality signature experience!
Connoisseur level shit, the way the heater is tuned and built, the materials used, not to mention the fact that the 2 were assembled by hand by Ryan closer to the old days (not 100% sure about the bodies, I think they were made differently than the original Milaana, certainly were easier to churn out in that square shape and get a wide variety of exotic woods)
For me a huge part of it though, is the superficial aspect, the colored glass and the exotic woods, these are the final reserved units with some of the best grain as well! If that sort of thing appeals to you, because I will say compared to the older walnut sapele bottom Milaana II I have now I actually prefer my Milaana3 performance vapor quality wise... I am going to have a new 2 from these last batch though, so we will see if I feel the same way, each one can be different really!
So not just superficial, the experience overall including performance and appearance, just makes each one unique, particularly when they are handmade like this... If you can afford it and you are a fan, well you can see why many of us here have so many of these! Certainly do not need it, many of us enjoy the collection though...
One final thing, Milaana3 uses the more customized 19/19 glass joint connection, whereas Milaana II uses the more standard 19/22 glass joint connection size (the second number refers to the length of the joint, often you will see 19/26 and those will not fit, and there is a lot of variance in glass stem joint connection anyway so you never know what could fit properly, need to be careful testing them, because you don't want to put any strain on the heater screen to risk potential damage... The first number, is sometime referred to as 18mm or 19mm and is technically 18.8mm) like the old RBT vapes, including the OG Zion and Milaana, new ZionM and actually all SplinterZ btw, used the 19/22 so yeah there is just a lot of benefit for a lot of us here for stem compatibility etc.