I did some research and didn’t find anything too negative towards getting this Phottix BP-40D vs a Canon BG-E2/BG-E2N as a grip for my 30D other than the make. The pro-point is that its only $75 shipped from Hong Kong to San Francisco. It has the same features as its Canon counterpart but for less. Here are some points from the eBay seller, etefore (aka. HK Supplies), of whom I got it from:

• The Vertical Grip/Battery Holder adds a vertical shutter release, and is compatible with up to two BP-511, BP-511A Lithium-ion battery packs, or six AA batteries with included battery holder. It provides additional shutter release, main dial, AE lock/FE lock and AF point selection controls for easier vertical shooting.
• The battery holder works with one or two BP-511/BP-511A batteries.
• Battery Holder for six AA batteries
• Instruction in Chinese/English/Netherlands/French/Germany/Italian/Spanish
• It also has a tripod socket.
• The battery grip and the batteries are NOT Canon made.
• These high quality product with big discount from the original one.
• Made of top quality materials and the best quality you can find in the market.

To add to that, based on Phottix’ website, the grip can be used on the following dSLR bodies:

• Canon 300D, 350D/XT, 400D/XTi, 10D, 20D, 30D, 40D, and 5D
• Nikon D200, D70s, D80, D40, and D40x

Here’s some photos of it (by Flickrite presspix):

Meanwhile, I’m hoping to receive it by either later this week, or early next week. I’ve bought from etefore before and they ship pretty fast. I’ll update when I have received it and have given it a test run.