Check out http://www.directbadminton.co.uk/search/badminton/voltric. Choose the filter to sort by price from high to low. It should now show you the complete range of Voltric rackets arranged from the most premium to the lowest.
voltric force should be low or mid range racket, zf2 is the top range racket however zf2 should be more stiff and head heavy
I have found from handling both rackets that the Voltric Force is more head heavy that the Voltric Z Force 2, but the ZF2 is stiffer. If you are looking to upgrade I now mainly use the Voltric 70, this is a lovely racket although its not as stiff as the other rackets. The best bet is see if you can borrow another Voltric racket as they all have slightly different feel. I have tried most of the voltric range and can't say any of them are bad rackets. Happy hunting.
Agree with bunge1980. VTF head heavier than VTZF2 VTZF2 stiffer than VTF If you like head heavy and stiff shaft, you can try VTLDF: Voltric Lin Dan Force. It is less stiff than VTZF2, and less head heavy than VTF. It has also a slightly larger head.
I also agree that VTF is a bit more head heavy compared to ZFII. Measured both. 44g headweight vs. 42 head weight in 4U. ZFII head is smaller and has longer shaft. Stiffness is would call both close, because the VTF has a real compact but longer head compared to ZFII so the shaft is shorter. What do you want to change with your new racket? If you like the F, you should switch to ZFII if you just want a high end.
