I just received mine yesterday and played with it a bit last night. It's a Meike for my T3i and I bundled the purchase with two aftermarket batteries. I figure on using them and keeping the single Canon battery as a backup if they go flat. The instruction manual states that when using two batteries, both discharge simultaneously.
The fit and finish is really quite good, as good as the factory grip though I do understand the factory grip to be a little beefier in construction, not beefier by $100+ though. So far so good, I'm quite happy with the purchase, especially for the bargain it was. The advantage of the vertical controls is worth every penny.