Heat pumps have less immediate heat and less maximum heat. As electricity conservation becomes increasing vital heating appliances utilizing heat pumps are increasingly becoming an option but those limitations remain.

For water heaters you just need to be certain it replenishes quickly enough for your needs. But for other applications like dryers you may find yourself frustrated with the actual downsides regardless of choice.

A lot of hate for heat pumps comes down to people using them like resistive or gas heating rather than like the backwards air conditioner they are.

Are they extra expensive? More complex install?

Like with an AC you need a place for the outside unit and do some piping. They are also more expensive, but the costs usually amortize well before a new unit is needed. They don't heat as hot, so you might need a bigger tank.