I believe they're all transformerless (XLII, XLS, LTD....even the older TLII). Not the old ULS, though.
That's my understanding, as well. I'm a new with my xls, though, so I'm as interested as anyone in this thread. I hope Skalinder chimes in as he ran xls for quite some time and in many different applications.
Another notion I hold, and disabuse me of this if it's incorrect, is that the xls is primarily for acoustic up close instrument mic'ing. That's why I got mine. I know they DO work well for that application, but I don't know that they don't work well for other applications, e.g., electric guitar amp mic'ing.
Finally, the first night I used them I had a problem with the wav squaring off on the bottom of the wav form (as described here with graphic wav image). I'm going to experiment with using rolloff & attenuation pads, and I need to rule out the reflection from the hard wood floor, as well. The squaring off happened to a MUCH lesser extent when I recorded a PA'd show from 30' back (also documented further down that thread I linked), which leads me to think it's an attenuation/rolloff issue more than anything else (or that something else altogether is happening). My concern is that Skalinder said he never used attenuation and rolloff and never had a problem. He didn't get specific on the applications, though.
Anyway, anxious to hear some more replies to this thread.
And Charlie, I think Steve will really dig whichever 414 he ends up with. It's a killer sounding mic and will complement his "sound" very nicely.