I have booked the Hyatt House off Rosecrans and the Huntington Beach Hyatt (it just looks lovely).
Will have to decide if it's worth the extra drive to Huntington Beach in a few days.

Thanks for all the food recommendations too

Huntington Beach would add 50-60 miles overall to your drive to Death Valley.

What day of the week are you landing at LAX? If Monday-Friday and you're not leaving for Huntington Beach by 2:30 or earlier, you're going to encounter terrible traffic. It won't get better the farther south you drive. Not surprisingly, Fridays are the worst. If you're landing on a weekend, it will still take 45-60 minutes to reach Huntington Beach.

Land at 1.30pm on a Friday.
I estimated it would take 1.5 hours to get to Huntington Beach. As my husband will be driving so I will leave the final choice up to him

Well, on the bright side, in your trip diary you would be able to add "driving to Huntington Beach just to have dinner and turn in early" as "one of the worst ideas we ever had".

Just for one night I wouldn't go down to HB. But if you decide to spend a few nights, perhaps as the hotel is nicer (but also not ON the beach, across PCH instead). Very few hotels are on the beach here, including the Marriott and Shade.

I think Manhattan Beach is actually a nicer place to hang out than HB, better restaurants and I like the walkway in front of the mansions (as well as the bike/jogging path).

I also worked in El Smellgundo and still go to MB often to visit with friends.

We will be staying at the Hyatt House, MB.

Huntington Beach was closer to DH's cousin but we will have dinner with them later in the week when we will be staying in Anaheim.

So MB for our first night, then 2 nights DV, a night in Vegas and 2 nights in Anaheim.
An odd mix of places!

The Hyatt House was absolutely fine for our first night. Lots of space which we didn't really need but we did use the refrigerator to store a few items for breakfast as we were leaving before the hotel breakfast was served.
After checking in we drove to the seafront and walked along Manhattan Beach until sunset.
Paul Martins was less than a 5 minute walk away so went there for Happy hour drinks and nibbles.

We flew home yesterday afternoon so before returning the car we spent another hour walking along Manhattan Beach, enjoying the sunshine and watching the surfers. Very convenient beach spot, close to the airport.

Overall a great trip; we loved Death Valley

Thanks for all the help and suggestions. Much appreciated!

Thanks for reporting back and it is nice to hear that the advice given was good and appreciated.

I love Death Valley too!

Glad to hear you had a good trip, yes Manhattan Beach is a nice beach town, quite laid back.

Glad to hear the Hyatt House was satisfactory and you enjoyed Manhattan Beach and Death Valley both.