Saw this thread (friend has a Highlander and I figured I'd look around to see what's on here) and wanted to chime in with some experience with glass replacement and Safelite as best as I can recall it.
First, our experience with Safelite was a good one overall. While on a road trip down to VA the windshield on our 03 Jeep Liberty just randomly developed a crack near the bottom center section of the glass. It was basically in the shape of a 7, only the leg of the 7 was straight instead of how it appears typed here. Called to have Safelite do the job as we were supposed to be heading back home in the next day or two, and it was covered by insurance. There was a local facility, so we brought it there and waited maybe an hour, no more than 2, for the job to be done. This was during winter, and even in VA it was rather cold at the time, though the vehicle was worked on in a temp controlled garage. We were told to leave the door windows cracked for 24 hours so pressure wouldn't build during opening and closing the doors and damage the sealing job. Also, they warranty the job they do against defects, so that's a plus, and we ended up putting it to use pretty fast.
The next day we're ready to head back home, and literally as we're packing the last of the stuff into the Jeep to head back, I get behind the wheel and there's the crack again, in nearly the exact same spot, and the exact same shape! :wtf::headbang::disappoin
We called Safelite, told them what was up, and decided to drive back home as it wasn't spreading and we honestly couldn't stay another day to have them work on it in VA. Once we got back home, there was a local Safelite that we coordinated to bring the vehicle to for another replacment, no charge. I asked the phone rep about whether this was a common occurrence or if their replacement was lower quality than OEM. They explained that their typical replacement glass meets the minimum safety requirments, but is certainly not as thick as OEM glass, hence the lower price point. They said that it is possible to get OEM quality (PPG, in this case) glass from them, but that it would cost more (obviously). Essentially to get the OEM glass we'd have to pay the difference for the better glass over cost of the original job, which was a few hundred dollars. It was worth it. The new glass has been intact and problem free for at least 3 years now, making several trips to PA and back, and it even came with a tinted band at the top for some sun glare protection, something that wasn't even on the original glass the Jeep came with.
Where I see the difference here with what has been experienced by others is being able to bring the vehicle to one of the company's facilities, where they can take the time to work on it as opposed to working on the side of the street or in a parking lot doing a speedy job. Safelite treated us very well at both locations and on the phone, and they made good on their warranty without any questions. I'd say, especially if insurance is willing to cover the replacement, spend the extra money to get glass that's the same quality as OEM. It's worth it, and from a safety standpoint, you can expect OEM glass to do its job in an accident and resist shattering like it's supposed to. I wouldn't personally want to take a gamble with something like that on the thinner stuff.
Just my rather lengthy 2 cents. Hopefully it's helpful to someone.