My neighborhood has major theft and burglary problems. And for last year I’ve had an addition being added to the front of my house. I’m a thief’s perfect target: an insecure construction site just feet from the street.
With a combination of research and trial and error (actually being burglarized), I’ve learned it’s most important to deter crimes from happening. Visible cameras, annoying alarm system signs, clear signs that a dog lives with you (if applicable), an extremely responsive siren, and quick, bright, motion-triggered flood lights are immensely helpful steering criminals away from your property. IMHO implementing some/all of those things properly is more important than the actual equipment selection. It’s better to avoid something happening than have a wonderful camera with perfect clarity on masks, flake plates, etc. You do not want to be a detective. You will not get your valuables back.
I’d suggest going with a security system that has a proven track record. Nest's and Ring's TBD systems are not yet the answer. I have a LiveWatch System, and it has successfully thwarted an intruder from burglarizing my house. It consists of a panel and an assortment of sensors. The panel communicates with a monitoring team via cell radio and your WiFi. It has a battery backup. The sensors are solid, reliable and all wireless. It covers the necessary corner cases, and works when thieves cut your internet, flip your main electrical breaker, and/or smash the panel, etc, all while you're not around to respond to an alarm notification.
I desperately want the quality and useably from Nest or Nest-like tech company. Sadly, Nest’s shiny new system isn’t up to par. It has far too many vulnerabilities for production with a limited sensor selection. Get LiveWatch, it’s the best for now and The Wire Cutter agrees. Or something similar. And it’s worth the investment over decades-old alarm system you have.