Are you looking for an at home PV? Or do you want something that you can carry when your out too?
The silver bullet, lavatube, etc are really nice, but they are pretty big. If its just for at home then it doesn't really matter, but if your like me and are planning on carrying it with you everywhere you go, then something like a silver bullet might be kind of a pain.
Also give some more info on what your looking for. Do you want variable voltage, a higher fixed voltage like a 5V, or do you not care about having higher voltage and just want something with a bigger battery that will last a lot longer.
And another very important question is how much do you want to spend? Bc there's bigger battery PVs that you can buy for $50, and there's ones you can buy for $250.
If you dont care about higher voltage/VV and want to be able to easily carry it with you wherever you go, then I would check out something like a kGo or Epower. The slim ecig you have now is 3.7V, and the kGo and Epower are both 3.7V but will give you a LOT better battery life. The eGo is also a popular bigger battery PV, but it is only 3.3-3.4V. So while the eGo would give you much better battery life, it would actually be a downgrade voltage wise, and that's why I think a kGo or Epower would be better since their 3.7V PVs. I personally like the 3.7v PVs a lot more than an eGo bc they provide alittle more "oomph" and handle the lower resistance attys and cartos a lot better. Both the kGo and Epower have very good battery life, but are still small enough to be able to easily carry it with you in your pocket, plus their very affordable. (you can buy both kits for under $50)
Personally I use the Epower and love it. I started with a slim ecig and wanted something bigger, but still wanted it to be easily portable so I bought an Epower. The biggest difference of the Epower compared to PVs like the eGo and kGo, is that the Epower uses non-proprietary batteries like other mods do silverbullet, lavatube, reo, etc. The other difference is that everything is replaceable on the Epower and each part can be bought seperately. That was one of tens things I really liked bc with an eGo, kGo, riva, etc the battery cannot be removed and everything is one piece. So if the switch fails or you need to replace a battery, you have to rePlace the whole unit. With the Epower you can buy a switch seperately or just a battery so you don't have to replace the whole unit which makes the Epower cheaper to maintain. I also liked that Epower batteries cost $4-5 compared to eGo/kGo/riva batteries that are $14-20, and the Epower batteries last longer before they need to be replaced. The Epower batteries are 1050mah so they last a long time and I get avg a day to a day and a half on one battery, plus their small so it's easy to carry a spare. I've been really happy with the Epower bc it allows me to vape all day maintanace free. A battery lasts me all day and I use a 3.5ml carto tank so I don't have to worry about refilling throughout the day, yet even with the tank on it, I can still easily carry it in my pocket.
The kGo is really nice too even though it's a proprietary battery PV. The batteries are 1100mah so they will last a long time and it gives a great vape, plus it's very affordable.
With either one I would try the Ressurector cartos. They work awesome on the kGo and Epower and give a great vape. The boges are really nice too, but I like the Ressurectors bc they hold almost twice as much juice, which means you can refill a lot less. Now I use the Ressurectors in the 3.5ml tank so I can fill it in the morning and be good all day.
I think you'd really like the Epower or kGo and have much better battery life, without spending a lot.
If your willing to spend more though then you can choose from a wide variety of tube mods that would fit your needs.
Goodluck with it!
