My Canon cameras (400D, 50D) I grudsätzlich used with the original battery grip. After the upgrade to the 5D MK III I was shocked at the cost of the original battery grip. Here is definitely my price acceptability limit is exceeded. After much research in various forums and the many negative reports about battery discharge and increased sensitivity of the joystick, I have - very skeptical - for purchasing of pixels / Vertax-replica. The battery grip is processed very neat. The gum is faultless and complies with the structure of the original gum. The fit is excellent. The service is impeccable. The pressure points of the auxiliary switches are orderly and largely correspond to the original. The trigger is slightly more sensitive with me what the real trigger point (ie pressed all terms). The joystick works felt somewhat imprecise as the joystick on the camera. Again, this is much more easily processed. All in all, but functional. The unlocking of the battery compartment is very delicate, but stable enough. The one negative I also strong smell of plastic / rubber etc., which apparently comes from the rubber. The smell is mitlerweile no longer exists. After two weeks of use, I can no battery discharge when not in use notice (here I was particularly sensitive). Considering the price (I paid 82,50) is the battery grip is a strong buy recommendation, for photographers who can live with the above-mentioned small but reasonable restrictions. A real negative point is the lack of seal of the battery grip to moisture. The originals seals are bypassed by attaching the battery grip, especially in the sensitive area battery. Thus the door is opened, the moisture in the camera. As far as I am aware, the original handle is also not equipped with seals. Therefore, no deduction in the evaluation of the replica handle.
Addendum of 06/10/2013 I have had the battery grip now frequently in use. Unfortunately, piling up failures the camera's internal electronics (eg thumbwheel or retrospect key without function). These errors disappear immediately after turning off the battery grip, so clearly the battery grip can be moored as a cause. I'll send in the battery grip now.