Love it or hate it, the Aural Exciter, along with its numerous clones and imitators, has been with us for 30-plus years and even though it's the antithesis of hi-fi, it must be doing something right. During this time, the technology has gone through various improvements and refinements but I find that even the basic Type B model from the mid 80s still has its place in the contemporary analogue studio, even though it might spend most of the time in the cupboard (I don't know about live applications).
As I understand, the Aphex Exciter was initially developed for treating dull-sounding analogue recordings. How successful it was in that has always been a point of contention but since retaining treble isn't really a problem nowadays, the Exciter has found its application in shaping sounds intended to stand out in the mix. For me, it worked well on drums and purposely distorted material, such as electric guitars, as well as on vocals. Needless to say, I wasn't going for a natural sound on the latter, though even with the added crispness and air, the vocals still didn't appear either overly bright or unnatural in the context of the mix.
With all the magic that the Aural Exciter may work on a track, I have a hard time imagining running an entire stereo mix through. Firstly, making everything brighter is bound to result in a tiring listening experience, but more importantly, many instruments, especially acoustic ones, develop noticeable distortion when passed through the Aural Exciter. Even on suitable source material, however, I found that it's best used in parallel on full-wet as it tends to dull the attack (best noticeable with drums) and suck out some of the bass from bass-heavy tracks.
After I learned its strengths and weaknesses, I liked the Aural Exciter for what it did. However, after I got a good deal on the SPL Vitalizer, I couldn't help noticing that enhancer technology has advanced tremendously and that there was little reason for me to keep the Aural Exciter. I was happy to see that there still appears to be a healthy market for them however, not just because I was able to sell it, but because it would be a shame for such clever piece of audio technology to become fully obsolete.