I would definitely recommend the Silver Bullet! I have both the 510 and 801 Silver Bullets and they're both great vaping PVs. I'm impressed with how well it works and how well it's built.
PROS:
variable vaping volts
easy to press button
egonomically placed button
parts are internally built so that nothing falls out when changing batts
2 easy to assemble pieces that are screwed together with a seamless join
changing batts only takes seconds
threads are sized nicely so no cross-threading occurs
no well around the atty connection so juice doesn't collect in it
sealed atty connection so nothing leaks inside the unit
510 has the best draw I've experienced
great vapor and throat hit even on low nic
exterior is sleek and shiny
solid construction - built tough to last
can be used as a mirror in case of an emergency
CONS:
a bit on the fat side when compared to other 6 volt PVs; not a problem for me though as it still fits in my hand nicely