I personally didn't like the hot water dispenser all that much. We had one that came with the house and removed it. It wasted energy, water ran slowly, the spigot was awkward to operate, and overall, it wasn't worth it for us.

What worked better in our situation was installing a proper recirculating line for hot water. This way, there always is hot tap water when we need it. We also installed a European-style 240V outlet and ordered an electric hot water kettle from amazon.de. It's almost twice as fast as typical US water kettles. But I realize that's a crazy solution that most households wouldn't want to do.

Having said all that, I do understand that some people prefer an instant hot water heater. That's fair. I do suggest installing a drain pan under all appliances that have a water connection though. That means: ice maker, dishwasher, hot water heater, water filters, steam oven, laundry, ... This is easy to do, when you build a new house or when you do a full remodel.

Installation is slightly more complicated, but a good plumber shouldn't have too much trouble. The only complication is that these drains are not expected to operate under normal circumstances. So, you can't use a standard p-trap, as that would dry out. Instead, our plumber decided to drain into a utility sink on the floor below. But there are a couple of other ways to build a dry stand pipe.

My problem with them is that they’re not hot enough. Not for proper tea, nor for sanitizing. I‘d rather just get an electric glass kettle like the Oxo cordless glass kettle or the Capresso H2O glass kettle.

Have one, wouldn’t do it again. The tank failed 2.5 years in, and our plumber told us 3 years is the most you can hope for. Thank goodness we were home when the leak let go. That house is under contract and we opted against one in our new kitchen.

An electric kettle is a far simpler and better solution. The hot water from a special spigot can cause problems with your countertop, as well as being prone to breakage.

I've had an electric kettle now for nearly 40 years and would never be without one! The one I'm using now is a Russell Hobbs - at least 25 years old. Love that old thing!

Also keep in mind that when water is heated it begins to put off oxygen and when it is kept at a high temp, such as with these dispensers, it continues to do so. This results in flat or lifeless tasting coffee, tea and other things. Much better to get a Bonavita kettle (and never reheat water).

More on why here: http://localmile.org/cafe/

Another issue is that anything built-in will usually cost more up front, will cost considerably more to repair, and will cost more to replace.