Okay it is Gun Metal for me. What really got me was the telescoping. Like my Bolt and have some extra batteries until I figured out it was the charger giving me problems. Will report back my experiences.
Been about 2 weeks working with the GS Sub 2.0 and I like it. First VV for me mostly due to the telescoping which works very well. I'll have to stay with VV now that I've experienced it. Just don't overtighten the battery plug on this as it is hell to get apart if you do. Lightly tighten it and let the telescoping finish the tightening for you. I use the Boge 2.0 and when it is new start out at 4.0 volts - like having a fresh battery all day. As the carto ages I bump the voltage to 4.2 to keep that sizzle and on the carto's last legs bump it to 4.4. Higher voltages and I get hot liquid on the draw. The 2 cartos I've used on this have doubled their usable life from 3-4 days to 7-8 days. BTW - It is sometimes hard to gauge someone's use of a carto so let me say I use the same carto all day every day and do not change when I use a different flavor. Since I go through about 4-5 ml a day this makes me happy and I hit the carto hard on each draw. I can vape at my desk at work in an open cubbie environment and my co-workers kid me as they can tell how my day is going by the vapor clouds.
I use 18500 batteries, the same as my Bolt, and battery life has surprised me. Occasionally when I am at 4.4 volts I'll have to change the battery late in the evening but I carry a spare anyways in case the battery did not fully charge as the charger may indicate. I'm sure if I used an 18650 battery I would not have this issue.
The only down side I've has trouble with is the fire button. You have to hit it square right in the middle of the button. Also during the last few days, the unit will shut off for some reason when I try to take a hit. I'm trying to verify why this may be happening and suspicion it may be I'm not hitting the fire button square. This concerns me as I'm doubting the button service life. I can turn it back on and it acts like nothing happened. Just an annoyance right now.
Now, the V-Core 2.0 tank. It is built very well in my opinion, no leaks, but it is very heavy even empty. I also have the same trouble I have with all other tanks except the carto tanks... dry hits. None of these style tanks seem to be able to keep up with me as I'm a very hard hitting puffer. If I let it sit a few minutes it will siphon up the juice and I can get another flavorful hit. But on the 2nd hit it will be dry again.
My conclusions are the unit is very good especially for the price because it includes the tank. Only concern is the fire button. I could care less about many of it's other features as I just change battery and set the voltage. This unit has taught me the joys of VV and I'll definitely have to stay with VV in the future. If you are a light hitter you will probably like the tank. I'll give my tank to a friend and he will enjoy it - no biggie for me. Recommend to a friend? Yes but will explain my experiences about the issues I'm having with fire button - could just be me after all.