The DC to AC inverter technology would be basically the same. The only difference would be the kind of protection the inverter provides for the batteries, aka, how hard it will suck the life from them!
In the case of these Tesla systems, it sounds like the answer is "very gently", which mean only a low capacity inverter is requried, which is actually cheaper (less amps is easier to work with).
Other things they might have done is play about with the supply voltage to the inverter. If the batteries are run in parallel and feed the inverter a higher voltage, it means the current is reduced for a given load. (Watts = V x A), and current is the bit that makes all the inverter bits expensive. Most off-grid solar inverters run from 12v or 24v DC battery stores, which means the current for a 1.5KW kettle on a 24v system (assuming 100% efficiency) is over 60 amps (double that for a 12v system), which is more than the current an entire house uses on 230v mains, so you can imagine the size of the conductor required... and then you have to switch it into an oscillating form and feed it into a step up transformer, so the oscillator needs to be beefy and so does the primary winding of the transformer!