I've had a Challenger for 3½ years and nothing has failed. I quite fancy an Invictus III but despite having tried virtually everything else I've no desire at all for any other make of mid market gun.
Even though the action is a variant of the Italian standard Rizzini design, IMO the fit, finish and build quality are unmatched in any gun from any maker at the Summit through to Maxum price levels.
All the original range from Summit to Forum use the same action regardless of bling level and all are very smooth to shoot with good handling and very nice clean, light trigger pulls. They really do make most of the competitive guns feel pretty agricultural in comparison. As for the patterns, the supplied Maxis competition chokes are so good that very few CG owners seem to fit aftermarket chokes.