All depends on your skill level, how you're riding, where you're riding (as in if you are a track day rider or not), etc...
Personally, I could have went with the ZX-10R and that would have been my choice for a literbike as it was either any Kawasaki, Yamaha or Honda at cost minus an employee rebate from the factory. I decided that since I'm no longer in Dallas anymore, although I will be again soon, the smaller town I am in, I would be riding around in 1st gear everywhere I went. Now if I were in Dallas, then I would have leaned more towards the literbike.
To me personally, I think a literbike can make you a lazy rider. All you have to do is twist the throttle on a literbike and it goes.
For me a 600, or in my case a 636, is just more fun.
How much riding experience do you have? Taken an MSF course? Been on a track? You really need 180hp? Not many need all that power, but it sure is fun, but what I'm trying to ask, would you use any of the potential in a literbike or would you get around 80% of out a 600?
I have a feeling this is more of a question if you need a 600 or a literbike and if you had a "Gixxer," then you should already know this. Something tells me you might not of had that bike for very long. To me a 600 series bike will make you a better rider, at the 1st half of your riding stint
Oh and by the way, It's called a "Gixxer" for slang, not a "Jixxer."
2014 ZX-6R 636: M4 Street Slayer Exhaust, FlashTune Bike Tuning Kit, Bazzaz Z-Fi, Z-AFM, MJS Headers, K&N Race Air Filter, RaceTech Gold Valve Fork Kit w/ Bottom & Top-Out Mod, reshimmed & RT Fork Springs, RaceTech Gold Valve Shock w/ Refreshed internals & RT Powdercoated Lime Green Spring, D.I.D Gold Chain, Vortex -1 front sprocket, PMP Sprockets Anodized Green +2 rear aluminum sprocket (-1/+2), GPVR4, Fender Eliminator Kit, MotoDynamics Smoked Integrated LED Taillight, '13 Lower Green Fairings, R6 Throttle Tube, Pro Grip Padded Tank Pad, Stomp Grip Clear Tank Pads, Pazzo IFX Candy Green Shorty Levers, Raskal Graffiks Wheel Decals, Puig Double Bubble Dark Smoke Windscreen, Driven Block-Off Plates, Driven Gold Spools, Morimoto Mini H1 7.0 Bi-Xenon Projectors, Morimoto 5Five 50w 6000k HID's, (6) Morimoto XC RGB Angel Eyes, Pirelli Diablo Rosso Corsa's, etc...