How long should the replacement battery last on this one?

My battery for my MBP 13" Mid-2009 finally went out and so I bought a new one from Anker via Amazon. I have been thoroughly disappointed in the performance.

iFixit was very helpful for me to install it, but as I've gone back to do a bit more research, I'm wondering if I should have just bought the one on here for $25 more bucks. Even now spending another $100 may be worth it since my "new" Anker battery lasts less than 2 hours.

All that said, can someone tell me either your experience OR the estimated battery life for this battery being sold on iFixit? It appears to be an Apple product, so should it last like the original battery for this machine?

Thanks.