Cambered vs Regular Bar

Today I was doing speed squats with the cambered bar and worked up to a heavy double. When I got up to 275 it felt real heavy and tough to lift, so I stopped there. But with a strait bar I can easily do 315 after my speed squats. Does the cambered bar effect anyone else like this? Another thing I can really feel it in my lower back after using the Cam bar.
Thanks in advance
Will42

The cambered bar definetly makes squatting harder. My friend who is a competitive powerlifter feels it much more in the lower back and glutes than a straight bar. The lever is different.

Yeah, the cambered barlowers the center of gravity and wants to pull you forward, so your lower back will really feel it.