Experience with adding super tweeter?

I tried the dual firing Aperion and another front firing one, the PTS I think, both with my Spendors (SP2/3R2) and Martin Logans (11A). Conclusions:

1. The dual firing one is much better built and sounding. If you like what a the supertweeter does to your sound, it's worth spending the extra money for the more expensive one IMO.

2. Both of them are quite loud. I found myself using them only on the lowest intensity setting.

3. The positives: they add air / HF extension and as a result the bass also seems punchier.

4. The negatives: the sound seems to lose color, it gets bleached or gray somehow; the bass seems somewhat disjointed; there is a notable effect of blurring the transients (must be some kind of interference with the speakers' tweeter).

In the end, I preferred the sound without them and returned them both.

thanks for the input. What happened to the soundstage (size, precision)? 

Soundstage became more expansive and enveloping, in particular with the dipole supertweeter, which was really nice. On the other hand, the precision of the imaging decreased iirc (not 100% sure on this one). There was a pervasive sense of diminished temporal precision, though, what I called transient blurring in the previous post. The bad effects were less significant the higher was the crossover set, so I preferred it at 16 kHz for the most part, but they were still there.

By the way, positioning mattered.

Makes sense, more 'airy', less 'precise'. 

For test purposed (proof of concept), would it be sufficient to get my hands on a 'super tweeter' (ribbon, similar) and make a simple 6 db/oct high path (with various crossover points to play with)?