Replacing Vintage Spendors is not as easy as I thought

I have a pair of 1989 era Spendor SP1 s and was thinking of updating them as I have heard of the vastly improved technology and materials used by current speaker manufacturers.  So off I have been listening to new speakers, many of which come advertised as natural sounding, or neutral etc. My search has been a bit constrained by my Leben tube amp which is a modest 32 watts. I have heard Harbeth, Aerial Acoustic, Devore, new Spendors, Totem and a few other brands all of which lack the natural vocal qualities of my SP1s.  Some are more dynamic but at the expense of more fatiguing treble.  I have limited my search to the 5000-7500 range but am coming up empty handed.  I am sure if I was ready to spend 15,000 +  I could find a good upgrade, but college tuitions preclude such an expenditure.  Anyone out there with any suggestions?
A lot of the dealers that carry Leben also carry Devore and pair them often.  If me I would take another listen to that combo.I think the smaller orangutans might be in your budget.Since your accustomed to Spendor maybe give Tannoy a listen,just a thought 
I would suggest that what you believe to be fatiguing treble is actually much more accurate treble but a treble of which you are not accustomed. An additional thought is that the newer speakers are much more revealing of the electronics than your old Spendors thus less forgiving of poor program material. You need to be very aware of what electronics are driving the speakers you auditioned and also the room in which they were demoed. 
.....or maybe you just prefer the sound of your old speakers. Nothing wrong with that. If you prefer the old speakers, no reason to part with $5000 - $7500 or even $15000. 

BTW, I stumbled upon a pair of Infinity RS1.5s, vintage 1980, a few years ago. Brought them home, promptly sold off my more expensive speakers, and have been living happily ever since.

My suggestion: Don't worry, be happy!
Agreed if you like your speakers that much keep them, Spendor makes great speakers and the SP1 is a classic. If you must have something new check out Audio Note, the AN-J, my current speaker, is right in your price range. 93db sensitivity it's easy to drive and very organic sounding. Whatever you decide good luck and happy listening.
Yeah, keep your speakers. Perhaps upgrading your source and/or cables would make more sense.
If you want to try something different - not British sound - I suggest you try Kharma. Used, new is too expensive. No idea how they would work with your amp, probably depends on model, you room, how loud you listen, what you listen to. But 32 good tube watts is not little.
I second jsautter above, what your ears are rejecting is the tweeter attack of contemporary speaker design.
Having said this, new Spendors 2/3 or the smaller Harbeths are an evolution of your own spkrs sound.
Otherwise, try the smaller ATC models, the SL 20 or the 40. Great midrange (as you’re used to hearaing)
Take a listen to the Vandersteen Treo CT
 I have a pair of 1989 spendorSP1s and understand what is engaging you.
Also, bring in your amp with you.
The Treo CT offers an exciting level of finesse that when used even with a 20WPC Quicksilver Tube amp their even-handed impedance load allowsTube amp's to perform well and have most scratching their head after a listen.  
 Best JohnnyR 
Give the Rega's a shot . Very natural, very musical , very liittle fatigue and easy to drive .
Lot's of great choices out there depending on your tastes.  I actually met AudioConnection when I wanted to upgrade my speakers to newer Proac's (I had Proac for over 20 years).  He forced me to listen to the Vandy Treo (not really forced, lol) and I fell in love. Surprised the heck out of me. They gave me what I love in the British speakers, but with more finesse as AC pointed out.  
I would be auditioning Audio Note speakers--I have never heard of anyone complaining about too much treble response with their speakers and they are quite easy to drive so they work with a wide variety of amplifiers (by the way, what amps would you be using with your new speakers?  It helps with making recommendations).

Someone who is a fan of old Spendors would also probably like ProAc speakers.  I am particularly fond of their stand-mounted D2 speaker, and their floor-standing speakers with ribbon tweeters (they are more successful at blending ribbons with other drivers than most speaker companies that try to do this trick).
Agree on Proac ribbons. The first ones I've had zero fatigue with.  AN (their more expensive ones with all silver caps and wiring) were musical in the way an FM car radio is/was.  They just didn't move me.  I like the Harbeth's better, but I like VAndy and then Proac better than the top AN speakers.  Again, this is why it's so subjective ...
I like the Harbeth's too, and they certainly do have some similarity in sound to Spendor vintage speakers.  For me, the slight hardness/sibilance in the upper midrange/treble region in all of their speakers, except the 40.2's, is a little bit of an issue, but, this adds a little bit of zip and liveliness to the sound so that might be a plus to someone else.  I feel the same way about Tannoy speakers--just a bit too much hardness.  That is why I prefer ProAc and Audio Note.

I on't know what are the current prices on Shahinian speakers, but that is another line that is easy to listen to and is not excessively bright.
There are some members here that sold their speakers and regret it .If you are ststisfy with your Spendors I don't see any reason to replace them.
I agree with itzhak1969.  If you enjoy your Spendors, why make the change?  Have you tried a little tube rolling with your Leben?  It might give your speakers a nice tune up.

I almost went for your same speakers back in 1987, but opted instead for Vandy 2C's; either would have been my first high end speaker.  My impression of the SP1's lingered for awhile, making me ponder what could have been.
Those Graham LS 5-9 speakers really caught my ear at Axpona a couple years ago.  Wonderfully natural sounding.
Here's another thought:  you clearly like the Spendors.  Maybe consider rebuilding their crossovers with higher quality elements?  They very likely use some electrolytic capacitors that are getting tired and could use replacing anyway.  Done right, you would keep the frequency balance character of the speaker and likely get a more informative presentation of that voice that you like.