No empirical data, but its going to be quite a bit slower. The JPEG format is much simpler and has been highly optimized over the years. It looks like its very similar to HEIF, which is based on the intra coder for h.265.. I'm guessing it'll be 10X (or more) slower).
the BPG is based on HVEC video compression standard which is ranked as twice as efficient as its predecessor H.264.
No special hardware is needed for the encoding and decoding of BPGs on smartphones and tablets since HEVC support is already included.
BPG combines both quality and data compression, so it simulates PNG in quality and transparency support, but apply data compression to reduce file size.
Yes, compression time is much more than that of JPG but decompression time is slightly higher than that of JPG. See table-1 of the file attached
@Jaafar, thanks for the paper reference. While useful, this isn't the best paper since they are compressing binary documents, using OCR accuracy as a performance measure, which isn't what these encoders are good at. They probably should've included the lossless JBIG2 (https://en.wikipedia.org/wiki/JBIG2) compressor in their results. The paper does reference a couple more papers, though, that might have similar results for (non-binary) images.