The ball is far better than just "better than nothing".

If you do it properly, you can get a killer workout! I was fortunate to take a ball class once and got a lot of great ideas from it. I'm trying to replicate it, but without the teacher saying, "Ok, great now another 20" I tend to stop before I probably should.

But if you have videos, that should really help with that.
I like to use 3, 5, 8, 10 pound hand weights as well. You can basically use the ball as a bench by resting the neck on the ball and supporting yourself with your legs. This works the butt and thighs at the same time as your arms while doing the weights. It's great and much harder than it sounds.
I love working with my ball! I'm going back and forth between getting a weight bench and just sticking with the ball and I've done both lifting with machines and ball work.