Which products are you trying to compare between the two brands?

If you are referencing the alumnium hard-side luggage of each brand, it comes down to your personal preference.

Zero Halliburton is a former American company, now owned by ACE Co Ltd, a Japanese luggage manufacturer. The company made the move, in 2017, to shift assembly and corporate headquarters back to the United States. The aluminum luggage is manufactured in the US from imported components.

Zero Halliburton aluminum luggage is significantly heavier than RIMOWA's Classic and Original aluminum products. Remember, Halliburton's original focus was industrial use; think Texas oil fields and their publicity in having gone to the moon in support of the Apollo missions.

RIMOWA is a German company, owned by LVMH, since 2017. The company has always made its aluminum luggage at their Cologne manufacturing facility.

In visiting the RIMOWA Cologne manufacturing facility, the quality has not changed since LVMH's acquisition of the company. The same assembly lines are used, with only the loss of a station to install the former add-a-bag feature being absent, replaced by an employee who affixes the metal placard and additional personnel to package the interior accessories.

The main change for LVMH has primarily been the price, mark-ups ranging anywhere from 20-40% on some models. In addition to the more limited distribution channels, this was expected from LVMH, as the company has the same practice for its other "Maison's".

RIMOWA's after sales service has remained the same (from my experience) in the two years since being acquired by LVMH.

Both brands suffer the same downsides of owning any aluminum luggage, they will all dent at one point or another.

At the end of the day, still your personal preferences and tastes.