I hear lots of negative comments on the Zeikos Grips. Most appear to be comments based on other people's comments rather than actual usage of the grips. I would like to hear from only those who actually purchased and used the grips.
For the record, I have one setting on my desk, but based on some of the comments, I'm afraid to put it on the camera (D300).
I tried one that was "new, in the box" with a good set of batteries at a swap a couple years ago on my D300. Camera stopped working. Took off the grip, all functions came back. Next day I ordered the Nikon unit. I've never had a problem of any kind with the "real" MB-D10.
My first one broke after six months. They were willing to warranty it out but wanted to charge me $15 for shipping and handling. I was able to fix it myself with some epoxy but I am not sure how long it is going to last. The posts that hold the battery clips on aren't supported on the top and will break off.
I did order a second one for my new D300s right before last Christmas and it was DOA. Every time I would put it on the brand new camera the whole camera would go dead. I sent it back and bought the MB-10.
The build itself is night and day. The Zeikos grip is all plastic. No metal at all. The MB-10 is a magnesium body. The price difference is huge and I can understand purchasing the Zeikos. That is why I purchased one in the first place and tried a second. But killing the camera like it did really concerned me.
I got one thru Amazon, it worked well until one day after about 60 shots into a session the whole camera stopped working, flashed ERR on the LCD and nothing worked. Had to remove all batteries, lens, and reassemble before it started working again.
The camera doesn't always register the battery pack either. I have to remove the Zeikos grip and reattach it. Haven't had this problem with the Nikon grip.
I opted to grab an MB-D10 for $185 on B&H when the opportunity arose - it's significantly built better and feels better in my hands. I've always been a fan of OEM but since I had a $35 gift card from a friend it only cost me about $15 so I thought I would try the Zeikos, but now it's on eBay.
Have been using one on D300s for over a year the first one was draining the the battery overnight took it back and this one has not had a problem. Also came with the all the battery tray options included