ok. Here goes.
I received my replacement unit a couple of weeks back, but wanted to really put it through some use before reporting back. Before anyone questions the quality of meds used I have run in between 1/4 and 1/2 oz of the following disp meds: Obama kush, green queen, animal cookies, cheddarwurst, and bubblegum - as well as my own: nysd, star trek, the purps and kief.
For convenience, I will refer to my previous unit as xp3 and this unit as xp4. That said, I don't believe there is any real consistency in runs. Like I have said before, I believe damn near every unit is different than the next. I guarantee neither of my units produced anywhere near the clouds of vitolo's vids - especially on 5. Something to keep in mind when people say this is the best or worst unit. My observations may only apply to my unit.
xp3 had 4 intake holes and ribbed capsules. xp4 had 2 intake holes and no rib on capsule. W/ xp3, I would get 2-4 great hits (no visible vape) starting at level 5, then just super hot hits at 7. W/ xp4, I get at least double the good hits at 5 (still nothing visible) and it is way more tolerable at higher temps. I typically start a session by heating to 7, lowering to 5 and hitting as long as productive before increasing heat to 7, lowering to 6 - same scenario ending up on 7 to finish cap. I only get substantial visible vape at 7 after it has been cooking a while. I still ascribe no real convection properties to this vape.
In an effort to increase vape production, I again blocked my intake holes. This helped, but not enough. I then put a grommet around the cap to ride on top of the unit - sealing the open oven. As there is nowhere on top of the unit to secure a grommet, I had to cheesily wrap a length of electrical tape around it. Now there was no air intake at all - verifying that the top is where all the air leak was going on. I left the top secured as described and removed the tape from the intake holes (still sometimes using 1 as a carb). This is how I found the unit to be most productive. I will have to find a way to make this seal in a less ghetto fashion though. I am absolutely not looking to increase air intake by punching holes or anything. I want more vapor in my air, not vice versa.
The capsules seem to work best when fully loaded, which tends to flare out the top and in turn cause damage to the sides when inserting. I really wish these were of a piece instead of a wrap - built in weakness. W/o the rib, I have had the capsule disengage from the unit twice while in the middle of a session. A cap is slightly just more of a session than I need, but there is rarely anything there if I come back to it.
The usb port seems to be tight and stable, but too much pressure is needed to insert the cable. Over time I still see this being problematic. I don't know if it would mess w/ the electronics, but I've seen magnetic couplings that are loose, but auto connect if you get them close together. As this is the weak spot on the unit, I would aim at alleviating stress, not promoting it.
All in all, I would say this is an improved version. W/ the modification sealing the upper chamber that is. This seal not only improved vapor production, but flavor as well. W/ xp4, I am able to utilize the higher temps instead of just discarding load after a couple of pulls.
Here is my temp filtration system: bigass roor - 18 to 14 adaptor - ascent watertool adaptor - whip - xp
Definitely a work in progress.