It's okay. Considering most of the Acer products are generally inclined towards VFM buyers, there's not much you can complain about. The first laptop I owned was an Acer. The after-sales service is okay. You have to go the service center (they're present in most major cities) with the laptop and get it fixed. Service can take a bit longer if the crowd at the service center is huge. A couple of people I know had to wait an hour or so. Don't expect them to fix for your mistakes (like broken hinges, etc), they just won't do it. Replacement of optical drive, keyboard, LCD/inverter issues, etc and help with drivers is the service they will provide.
It's tough to match Dell's on-site warranty though. Dell sends a technician to your home/office next working day (after Dell reps are sure the problem exists and there's nothing else they can do) to fix the hardware problems or replace parts. Doesn't get any easier than that. But then again, Dell products are not dirt cheap like some of the Acer ones. But if you've decided in favor of the 5920, go ahead.