We've used Selfdrive 4x4 three times now, and have always had a great time. The routes are well thought out and exciting, whilst remembering it's a holiday so keeping the km/day sensible. Accomodation choices are all great (those that are a bit less good are in the parks so no other options).
They are happy to discuss customisation to standard trips and we made a few tweaks to most trips based on what was our favourite place/campsite on a previous trip.
Car was reliable and over three trips, 10000 km, we've not had a problem - not even had to change a tyre.
Strengths
Quick to respond. Well designed trips but with some flexibility for customisation.
Improvements or suggestions
None