Kinda depends on what you mean by high power, and also what your hunting applications will be, as well as personal preference.
For smaller caliber varmint cartridges, a 4x power is, in my opinion, too low for long range shooting (200+ yards at small game).
If you use it for hunting for big game, like deer, and shots will be within 100 yards or so, then 4x is fine, although some people, even under these circumstances, still like higher powered scopes.
The advantages of fixed power scopes is that they are, all else being equal, lighter and shorter, and have fewer lenses internally. Other than that, the variable 3x-9x (or thereabouts) is ideal for most hunting applications, and with today's manufacturing are just as reliable.
Zachary