Proac 2.5 Response tweeter upgrade with Ribbon Tweeter?

Has anyone tried replacing the tweeter (mine is Scanspeak 2010 851300) on the Proac 2.5 Response (mine is a clone) with a ribbon tweeter? Would it match or is this just a silly idea?
Thx for any comments or advice,

Today we auditioned the Tannoy Turnberry GF. Wow! My amp had no problem driving these speakers. Whilst the specs say that the bass only goes to 40Kz it was a much more musical and real. The sound stage is huge and 3D (compared to my Proac 2.5 and the D48r's) Clean sound and transparent too.

My wife liked them but was concerned I might be playing them at the same volume as we tested today. I said, "not quite - just seeing what they can do through my amp" I actually took my SUT, Phono, Pre and Power amp. All great except for a hum which I think was just the set up in the shop environment. Would speakers cause a hum? The hum increased with the volume control. This doesn't happen at home.
The shop use their turntable, tonearm and cart. They produced a very high Rez and resolving sound. I think my Garrard and ebony tonearm would mitigate the slight brightness that we heard and suspect was their t/table, arm/cart combination.
Thank you, 

Glad you like the Tannoy speakers. I am sure they are a much better match for your amplifiers.

 "The sound stage is huge and 3D (compared to my Proac 2.5 and the D48r's) "

If you don't have a huge 3d soundstage with the D48r something else is wrong

(((If you don't have a huge 3d soundstage with the D48r something else is wrong))Yes in total agreement. They play music without ringing artifacts.To some folks, ringing offers a short term wow factor.
 Best JohnnyR
2. If I want a speaker of this ’ilk’ (2 woofers + Tweeter and crossovers) that needs serious drive power then I would need to purchase a new amplifier. However, I would rather investigate other speaker options so that I do not need to change my amplifier.
As a general rule of thumb, if you want to get the most out of your tube amplifier, its in your best interest to avoid 4 ohm speakers- and this includes speakers that are rated at 8 ohms but have dual woofers such that the woofer impedance is 4 ohms.

So when I see dual woofers I make sure to find out what the impedance is at the woofer frequencies! If its 4 ohms its going to put your tube amp (regardless of the tube amp) at a disadvantage.
Now its also a simple fact that most amplifiers regardless of technology make less distortion into higher impedances. So 4 ohms means in general you will be hearing more distortion- and the ear converts all distortion into tonality, so this usually means 'brighter and harsher' with less detail than the recording itself. All in all its worth it to seek out those speakers with higher impedances- for one thing it means that the designer is listening to his product with a more discerning ear.
Thank you !
8 Ohm's it is. I've heard the results of 4Ohms first hand now - not pleasant.
Thx, Bob