"Only downside I’ve noted so far is the inability to phone them directly, which is slightly odd."
I have spoken to them on the phone but I also think the "inability" to phone them is probably a factor in why they are able to offer such attractive fees through reduced staff numbers. E-Super has heavily invested in the software and technology to automate much of the process.
I've been with e-Super for maybe 4 years couldn't speak more highly of them - very simple once it's set up and I haven't had any issues. Only gripe would be I ditched commsec years ago and really despise it although it was a requirement to use on establishment of the fund.