Maybe try something with more power.
A Silver Bullet can be switched between 6 or 3.7V, so can the Super6.
Also, (cheaper solution) you could try a BE112 (801) passthrough.
I think the BE112 attys are the best in the industry, but that is just my opinion. I have just about every atty and cartomizer and cart on the
market.
The BE112 passthrough I have does not have a in-line batt, like the 510,
but the BE112 cart hold TONS more juice that anything out there, and the
attys are very well made.
The vapor I get from the 112 pass is almost the same as w/ a 5V PV,
only problem is you have a wire sticking out of your e-cig.
I do like the Joye 510, but would recommend something with more hoursepower for you, esp since you are vaping tobacco flavor juice, which
tends to vape better with a 5 or 6V PV to get that real "throat hit".
If for some reason you want to stick with 3.7V, maybe your favorite juice
tastes better at 3.7, the eGo is the best PV. Consistent hits, lots of vapor, and the batt lasts a long time. Only problem is, the batt is special
made and expensive.
I think the best is the Silver Bullet or Super6 because they are versitile and can quickly switch from low to high volts in seconds just with a battery change

and the batts are easy to find and cheap to buy.
Try one and I know will will love it, either one (the SB is considerably cheaper though!).