I have mostly variable power scopes, but when I hunt I usually put them on 4-5--6 power and leave it. I rarely take a shot over 150 yd, and if I had a longer shot I probabally wouldn't take the time to adjust power up. take the shot, if it is a good one and you have confidence, don't take your eyes off the target. Now when I lived in Nevada that is when you need a variable power.
I feel that most people would be better served if they bought a 4 or 6 power fixed. Just think how much better quality of optics you can get for the money. And remember, the more parts, them more things that CAN go wrong, even with the best.