Costco Inverter Advice (Champion vs Diehard Dual Fuel)

Looking to pick up a small, suitcase style inverter generator from Costco. Was eyeballing the Champion 4,000W which is listed at $730 but then noticed the Diehard 5,000W just went on sale for $579. I'm brand new to generators and am not really sure the pros vs cons on each. Just looking for backup power during the winter for my house, possibly use for future van/rv/travel trailer. I plan to run propane.

Similar: size, somewhat similar running watts

Different: Diehard has the l5-30 plug while the Champion has the tt-30. Not sure pros and cons on either option.

Champion seems to have quite a bit more reviews both on Costco and online and seems to have legit warranty. Diehard warranty site linked from Costco doesn't even list generators, just a bunch of other power tools and power banks. Looks like a Pulsar to me.

Appreciate any help/advice to help make the decision.