The lag time from reading the CD is common due to the unit verfiying information on the CD matches the table of contents of the CD. An aftermarket player probably will take as long, as well as the OEM unit in an Limited.
As for the manufacturer of your unit, I believe its a Clarion, though I could be wrong. It changes over the years as well as between trim lines. I know that my '12 Limited is a Panasonic. You next question about if the upgrade sounds better. You'll probably get as many answers as those that answer. Some think it's great, some mediocre, and some horrible even on it's best day. Most people with a base or premium model tend to agree that the add on tweeter from the dealership is a good start in terms of upgrades.
As for the manufacturer of your unit, I believe its a Clarion, though I could be wrong. It changes over the years as well as between trim lines. I know that my '12 Limited is a Panasonic. You next question about if the upgrade sounds better. You'll probably get as many answers as those that answer. Some think it's great, some mediocre, and some horrible even on it's best day. Most people with a base or premium model tend to agree that the add on tweeter from the dealership is a good start in terms of upgrades.