Just want to give you my opinion on the Infini. I have a 3kW unit installed in my house now for 3 years and no issues.
Just to clarify the difference between Grid-Tie, Off-Grid and Hybrid.
Grid-Tie is when you supplement the grid either by feeding back into the grid or just to supply enough power to your appliances when using grid limiting device, no batteries invloved.
Off-Grid is when you make use of batteries to supply the load, the solar panels charge the batteries and the battery power is converted to the 220V, when batteries run low, it switch over automatically the your backup (Eskom or generator)
Hybrid is a combination of Grid-Tie and Off-Grid, so you can Grid-tie and run feed some major appliances with solar power with or without feeding back into the grid, if you have pre-paid, then sorry, you need to have an energy meter connected that will do the grid limiting. On the battery side of the inverter you can then have some essential loads that you can power for instance when Eskom is out. So some suppliers spec the Axpert Off-Grid inverters as HYBRID, but in fact they are only off-grid.
The 3kW Infini can give you 6kW output when connected to Grid, but only 3kW when grid is not available.
Thanx for all the input from different users and their opinions