It's basically the same, as far as I can think of. Robust Adaptive Sampler is the new default and should be used especially with the path tracer.
You can now control the number of light paths calculated per sample, which wasn't an available setting previously. So that can help reduce noise, depending on the situation. It does increase render time, but I often find it to be better to increase paths than to increase AA the amount that would be needed for a similar noise reduction. That being said it really depends on where the noise in your scene is. Higher max paths is mainly good at reducing noise in shadows where there is a lot of bounced light being calculated.
Other than that, maybe you can describe what your preparation process was under 4.3 and that might help illuminate any other potential need for changes in your workflow.
- Oshyan
