I can add to this with my anecdotal evidence. In my experience (looked at ~15gb of basecalled data total), there is a large amount of indel errors.

The mismatch rate is much lower. But it's hard to calculate exactly the mismatch rate when the indel rate is so high.

No citation, just personal experience aligning the data and comparing it directly to a hiSeq run of the same DNA.

I was able to get about 1-10% mutation rate, with a median of about 1.5%. Rate depending on quality of the run. In general it was on par with PacBio.