I have one as well. As DIYEngineer235 said, it has decent accuracy and it's very quiet...since it's a fairly low powered rifle. It's lightweight, ergonomic and has enough power to deal with very small pest, such as house sparrows, squirrels or mice, if necessary. It's fun to shoot and ideal for backyard plinking. The scope that Umarex packages with the gun is okay, for what it is (I'll probably upgrade). The single stage trigger has a long pull, but it isn't bad. I'm currently shooting Crosman Premier Pointed 7.4g, and Gamo Tomahawk 7.56g.
The only issue I've seen so far is trying to get both CO2 cartridges to puncture. Umarex recommends using their "High-Grade" CO2 cartridges, but I have yet to try them since they are more expensive than the Crosman brand. I've tried the "dime between the cylinders" method that DIYEngineer235 suggested, with some success, but I think I'm going to 3D print a spacer.
Also, if you plan to store the gun for an extended period of time be sure to remove, or fully dispense, the CO2 cartridges. CO2 can damage the seals over time. In fact, a drop of Pellgunoil or silicone oil on the end of the CO2 cartridges, between each change, will help to prolong the life of the seals.