Are Harbeth Super HL5 XD right for me?

I have those speakers. I took a chance and bought them used about 4 months ago. They have a front port so I doubt you will have a placement problem. I’ve owned many speakers including other Harbeth models and these are outstanding.

If you take a look at my system you will see that they are placed about a foot from the rear wall with windows behind them. You should look for a used pair just in case they don’t work out.

BTW, make sure you get the correct size stands to match them. You should check all listings for a used pair before you spend over 8 grand new!

TMR has a pair listed here for $4000. Grab them!

I'm a Harbeth dealer......  I don't think you'll have issues with them being a foot of the back wall.  They should sound really nice with your amps!

Are you in the states? 
I always felt Harbeth were a poor value on this side of the pond. A nice, well designed/built product, and respected history…but still.

In the similar “new but vintage look and feel” category, I’d suggest looking into the Tannoy Cheviot, which is more efficient, has a wider frequency response, (slightly) less expensive and more tuneable via the front panel. Their controlled directivity also helps with rooms that may otherwise be difficult. I listen to a lot of jazz at lower volumes (when my wife is asleep), and own the larger Tannoy Arden. They work great in this situation.

Jeff’s recommendation of AudioNote seems a solid choice too, although I thought they liked being placed in corners, which doesn’t sound like you have in this room.

You would have to listen to the Harbeth Super HL5 XD to learn if they are right for you. It is not mentioned in your post if you have ever heard these speakers before.

You need to locate a local Harbeth dealer , if you have one near you and listen for yourself. You can have the speakers placed near the wall behind them to experiment. The dealer might even be able to set up a home demonstration for you. The link below will show you local Harbeth dealers in the USA.

https://fidelisdistribution.com/brands/harbeth 

If you do not have a local Harbeth Dealer ,your next best option would to be buy a pair of Harbeth Super HL5 XD on the used market and try for yourself. If you do not like them ,you should be able to resell them for little , or no loss for what you paid for them.

Are Harbeth Super HL5 XD right for me?

op - no one can tell you this...

but most who are knowledgeable about speakers will say that the harbeth is a superior speaker to you klh5's in most performance attributes, with the possible exception of bass response