You did it the installs yourself or through contractors?

Fully DIY unless I reach a point where I think I've bitten off more than I can chew. I haven't started moving circuits from the main panel yet, but I'm confident I can do that and meet code. I may call in an electrician when it comes time to convert the old main panel into just a main breaker and wire its output to the PV inverters, but that's mostly just to make sure that part is safe and up to code.

How many years do you reckon it takes for that scale of solar to pay for itself

Not fully sure. I've got about $7,000 invested so far just in components and materials plus probably another $1,000 or so on the horizon for another 4 panels, wiring, and other accessories. The two 16 KWh batteries are the largest expense ($2600/each) since grid-tie isn't an option for me. Electric rate is currently $0.26/KWh and rising, so this is mostly a way to insulate myself from further rate increases as well as provide backup power (I re-allocated the money I was saving for a whole house generator to the batteries for this).

Very, very rough math estimates at current rates, break even is just over 8.4 years. That's $8,000 cost divided by $0.26/KWh divided by 10 KWh per day (5 hours @ 2 KW) divided by 365 days in a year. That break even time could be reduced by adding more panels (already planning to) and/or electric rates rising more (they sure aren't going down anytime soon/ever).