Thats a new one to keep your haixs clean! I have an older pair of haix pull on bunker boots. I have to say they are the best bunker boots I have worn! I know they make good boots and either way you go zip up or pull on you'll be more comfortable than any rubber boot! personally I would use pull on, unless your pants roll down far enough grab the zippers then you'll bre fine.
I wear the Haix boots every day and love them. I have worn Haix boots for about 8 years now. The soles can be hard if your standing in the them for long periods of time on concrete. I like also being about to adjust the fit with the laces.