Thoughts on hyrdonic boilers vs. conventional

I am preparing to replace a traditional cast-iron boiler and am considering putting in a hydronic combi boiler/hot water heater. I see positives on saving energy and floor space. I've also seen reviews that state the water heater in some combi units have trouble monitoring usage and can be inconsistent.

Anyone have experience with these units they can share?

I see models ranging from $2K to $10K. Would I regret purchasing a lower-end unit even if it has a strong warranty?

Brand/model recommendations are welcome. This is for a primary residence in update New York, so there's fairly heavy heating demand.

Thanks,
Dave