Since it's been officially released can give early numbers on certain aspects of it....
First will touch up on the charger/battery sent with the mod. It's an unbranded blue 18500 at 1500mah protected li-ion battery. The charger sent with the mod is a 3.7v/300ma charger (which means it's really a 4.2v charger). From a full drain of 3.2v on the battery, took 6 hours and 6 minutes to charge. You can use other 18500/18490 cells in these, do not use IMR (high drains) though. As Snow sir elluded to, this mod is based off the bolt. Bolt's do not have the best track record with high drain cells. There is no indicator (other than taste and vapor output) on when the battery has run out or gone into deep cycle mode. When you start noticing a drop off, charge them is my suggestion... The mod will stop working at 3.23v on average (small sample thus far). As for what voltage they come off the charger at, 4.22v on a very small average sample (7 recharges thus far- 4.21, 4.22, 4.21, 4.23, 4.22, 4.22, 4.23, and 4.22).
On to voltage output, still doing the voltage panel but will give a few glimpses into what to expect. The only thing that controls the voltage is the battery itself. In other words if it came off the charger at 4.22v, when you check it with a multi off load, the mod is running at 4.22. On load different story-
Cool cart 3.3ohm- 4.18v
Wow carto 2.3ohms- 4.16v
Dual coil 2.0ohms- 4.13v
Dual coil 1.5ohms- 4.11v
Just like with the egos without the king diamond ic's and high drain batts to power them, these batts quickly fall down to the 3.7v range in use and stay there for a good part of their cycle (again official numbers are in the works).
As for the name all day, all depends on how you vape. Have killed one of these in as little as 87 (use time) minutes with heavy vaping and a dual coil at 1.5ohms. Know some people who only go through one XL KD battery in a day (410~ mah) so for them this battery would last a few days. People who go through 7mls or more a day in dc tank will not get all day use out of it, but more time than the 900mah egos (think of it this way, you'll get 2/3 more battery life theoretically than the ego with this mod).
The button is stiff but not hard to push, and is pretty responsive thus far. One major complaint or praise that will be given depending on prefernce (again) is the draw. While not as tight as the ego, by no means as loose as the king diamond batts. Think the ashcap batteries xl autos (6.5 on the Mor scale for those wondering). There are only two air intake holes on the collar, but the post is notched so it's not completely crippled.
Long term durability, along with other quirks, are still in the testing phases (though since it is based on the v2 of the bolt, know what to expect). Will have the voltage panel up hopefully on tuesday.