Hi Andrea, the outcome with white set plaster is dependent on the skill of the applicator. "Dry wall" finishes such as Gyprock are not as skill-dependent and so are probably the more reliable option if a uniform flat surface is your desired result.

Dry wall over brick will likely be slightly thicker than plaster, depending upon how it is attached, so that might also be a consideration that tips the balance one way or another.

I suggest talking with both trades to help weigh up want works best in your particular context.

Thanks for your feedback John. The tradesman came did a little sample wall and I am very happy with the look of the white set and the fact that the cornices, architraves and skirts don't have to be taken off is a huge plus. As I have never seen the white set before I am unsure how it will be with cracking etc eg when trying to hang picture etc.

Hi Polly, not sure where "Andrea" came from before, sorry about that!

Yes, you will have to be more careful with white set when hanging pictures or otherwise attaching anything, but if you're happy with the look and it is more efficient to keep the trims in place, then white set could be your best bet.