1st time roof replacement, looking for a little advice on estimates

I got a few estimates for a new roof, and just had a few questions regarding materials.

For reference, I’m in So Cal, so we don’t get snow/ice, etc, but we do get a lot of rain some years, and heavy winds. Along with this we have some serious heat in the summer time.

I narrowed it down to two contractors, and they are both pretty close in estimates, but one estimate is written for Owens Corning True Definition Cool Duration Plus shingles, while the other is for GAF HDZ Reflector Series 30 year shingles with raised-profile ridge caps.

I’ve researched both (as far as I can with the internet), but I’m not sure which would be better for my situation. I know the company installing the Owens Corning showed me the materials and went over how they install the shingles, and also the two separate layers for sealing - one synthetic underlayment, and one self-adhered ice & water barrier. These seemed like a good thing, as the reason for my roof replacement is that it’s leaking.

I have looked at the marketing materials for the GAF shingles, but I don’t see any mention of water barriers, etc. So I’m wondering if this is something that isn’t used with these shingles, or are they just not mentioning them?

Also - wondering if one brand is better than the other for this type of So Cal weather?

Maybe there are some questions that I need to ask the roofers, but I’m not sure what they might be, so any help w that would be helpful as well.

This is my first time roof replacement, and I’m hoping it goes well.