I have a Leupold VX-III 4.5-12x50mm on my .204 and I love it. On my .22-250, I have a Leupold VX-III 6.5-20x40mm and I've discovered that 6.5 power isn't quite low powered enough for the "close in" shots. The 4.5x has been great. If you're considering Leupold, I'd highly recommend the Varmint Hunter's reticle. Both of my scopes have them and they are terrific.
Regarding a 3-9x, I've just experienced too many occasions where 9x wasn't enough. I find long range groundhogs require more umph....