Best compression for single cell RNA-seq object

I generated a scRNA-seq object (counts, PCA, UMAP embeddings, DEGs etc.) in Scanpy or Seurat. What is the best data structure to store this in to reduce the size of the object?

I’m considering H5AD (scanpy/anndata), RDS or H5Seurat (Seurat), or Loom

Fast loading/access would also be good of course, thanks