OK, ladders are better than bells, but they're not amazing.
Your options are;
In tank diffusers, simple, you can see what they're doing, but they aren't the most efficient (far better than your bubble ladder though), block up sometimes and need cleaning.
Inline atomisers, cuts a pipe, blocks occasionally and needs cleaning but diffuses amazingly well.
Inline reactors, more fickle than the atomisers for diffusion, but far less likely to block, needs a good flow rate and can slow down the flow, which can be a problem.
The jury-rigged route, some people tee the CO2 outlet into the filter intake. Works very well but does risk creating CO2 pockets within the filter, cheap and doesn't block though.