Here in NJ there is no glass only coverage so I can't attest to OEM for that. Glass in NJ falls under comprehensive coverage so we don't see many claims for it since there is usually a 500 or 1000 deductible. As for repairs we have to use OEM parts. They can be used OEM (that's with any company) but they must be OEM.
Want an honest opinion on claim handling with insurance companies call a coupe of reputable body shops in your area and I'm sure they will let you know who to use or not use.