Bear is right, EFI generally speaking is a huge improvement. Keep in mind most of the people here are have the experience to properly run the choke. If you are that interested in the EFI, I would say get it. That way you can't look back and wish you would have gotten it. I don't think you will be disappointed with the 700's power.

 

I know that this is a little late reply but I just saw this post I have a 700EFI and just went out and started it after it has been setting for 3-4 weeks turned the key pushed the start fired right up. I live in eastern Oregon and haul plenty of wood. It does great. As for working it hard the weight of the machine is an added bonus. I hooked to a locust tree that we cut down guessing it weighed in excess of 2000lbs (I don't pull this much normaly and probly wouldn't recommend it) to get it to move I had to tug against it and keep pulling hard. It has plenty of torque. I can't say anything for the 650 but if I had to guess the only thing the 700 has on it is 50lbs and a no primer