i never had any issues with my old 4x weaver, probubly the perfect magnification. ive found 4x to be good to 100 yards with pretty good precision and low enough for shorter shots. my current setup has a 3.5x10 pentax and id wish for an adjustable objective if i had it to do over again. especially at the higher mags.
Depends on how it's to be used. Could warrant a nice variable, a nice fixed, hi-power, fixed power, plinker, etc...
I prefer Burris myself but for for a more economical choice, I'd use a Simmons. Would bepend on how I was gonna use it.
For right now, I would imagine that the Leupold will do you well in most applications. If you are going for real accuracy shooting, make sure the scope is parallax free at 50yds(.22 scope) or has an adjustable objective(AO) lens. The AO scopes are especially helpful on 10+ power scopes.