Hey there,
I'll try to address your questions, owning several SaberForge hilts including the Exhalted, Prodigal Son, Redeemer, and Fury.
The thin neck sabers initially were not as bright as the regular sabers, because of the thin neck design and the fact that the LED is housed much further away from the blade than with other hilts. However, the reflective piece of film material inside the thin neck was recently added by SaberForge to compensate for this issue, and now all the thin neck sabers come standard with this reflective material lining the inside of the neck, which makes them just as bright as standard sabers.
The Exhalted, along with Redeemer and Prodigal Son, do not easily accept blade plugs...at least, not if you just try to use the blade plug out of the box. Check out
THIS THREAD here on the forum, as myself and another user have made some modifications to our blade plugs to allow them to fit within the Exhalted and Redeemer.
Allow me to also throw in a personal note: I LOVE my Exhalted. It's my favorite hilt. I first bought the Redeemer and Prodigal Son, and the control boxes, while screen accurate, were such a pain to duel with. The Exhalted removes that issue, and is one of the most comfortable hilts to duel with. PLUS! It is simply gorgeous!
So I say buckle down and get an Exhalted. You will not be disappointed