Definitely. I bought one of the "knock-off" battery grips. Feels great, and adds a significant amount of weight to the T2i. It arrived yesterday, but I'm still waiting on the batteries. Definitely worth saving up for IMO.
Battery grip: totally worth it. Feels like its an OEM part. Adds weight and bulks it up. VERY NICE!
Batts: Their great. I don't use the battery meter much, just when it hits BLINKING RED, i switch them. That's all I need to know! Last as long as teh OEM battery and charge as fast too. I got 5 for $24 on ebay, so you could get like 12 or 13 for the price of one OEM battery. VERY NICE ALSO!