I owned a non restricted Vector and have shot 4 Tavors (never owned one though). I prefer the Vector and even though I sold it I would still own another one. I think I would get the restricted version next time though. The only reason I sold it was that it was $2000+ into a carbine that didn't do anything that something else I had could do just as well or better.
The action of the Vector is awesome and super simple. It's really easy to clean and it's actually quite accurate, I was able to hit the gong at 200yds fairly regularly using the flip up sights. The rifle is reliable and ate all ammo I fed it.
The flimsy stock? Who cares? It's not a precision rifle where it would actually make a difference. It's strong enough and won't break or fold unexpectedly.
Cost of ammo? Well considering Canada Ammo sells 1000 rounds of norinco 45ACP (which my Vector cycled well) for $400 and cheap 223 is typically about the same I'd say cost to shoot is a wash.
The Tavor is a cool rifle and the 223 cartridge has potential but the platform doesn't seem to be very accurate unless you are shooting ammo that costs $1/round or more. Most reports are about 4moa from the Tavor which is fine for a battle rifle design but I expect more if I'm going to shoot 223. If it came with the improved trigger now available from Geissele or Timney it would be a much better value.
I think they are both good and the only way you will know which one is right for you is to shoot them both and see which one is more comfortable to you.
To the guys that don't like the barrel shroud on the Vector it can be removed with one allen head screw but it looks silly without is as well. That's the price you must pay for the non restricted status.