Steve, I know that this is a recall on the Power Clear 180 but wondering if the ethanol in the gas is also causing the same type gas leak in the 421.
The gas leak in the PC180 has nothing to do with the 421Q. They are different engines, parts, and production dates. If anything, Toro would make sure that the widespread problem of the PC180 is not duplicated in 2011 production. Toro has pretty much captured the market share for single stage. Widespread blunders like the gas leak costs a lot to rectify once the 221/421 units get out in the field. Not to mention the liability for personal injury and property damage.
I'm with Steve on this one. You can only worry so much about it, not one product is perfect. It can be, but it would costs too much, but the engineers would not stop working on it, and you won't get to buy one until the marketing folks shoot the engineers.
If you don't have faith in Toro product, well, there's Honda. The HS520 has been around for a while, most bugs have been worked out. Except the occasional component supplier change that may occur every so often. Keep a spare carburetor on hand.
I assume that you are interested in the 421Q because you favor the 4 stroke, quick chute, and the good reviews. Toro must have done something right to get your interest. What else is out there comparable?