Just to see, I took a tape measure to mine and the measurements in the manual seem pretty accurate:
240mm(~9.4inches) x 330mm (~13 inches) x 175mm (~6.8 inches) (W x D x H)
Not sure how large the Burson or the Pendant are in comparison, but yeah, I don’t think of this as a small amp. Also, this might be obvious, but you’re not going to be stacking anything on top of the Allnic, so no space savings in that direction either. The Allnic /does/ rest on some feet that are inset from the actual footprint of the amp, so going in the other direction, you actually can stack the Allnic on top of something slightly smaller than it. I’ve been able to stack the Allnic on top of my Exogal, the top of which is 7.45" x 11.5".
I don’t own a VC, but for what it’s worth, my Eikon sounds wonderful off of the high-impedance output. (EDIT: I recommend using the low-impedance these days.) I mostly use my Eikons with Auteur pads, but yeah, there was a really nice improvement in bass impact and a small boost in overall detail and stage on the Allnic for me.
I think I remember a slight burning smell for maybe a day or two, but yeah, I definitely don’t have any sort of burning smell on a regular basis. Also, I tried adjusting the volume a couple different ways and I couldn’t get my Allnic to make any pops or clicks, though mine was purchased used, so maybe my volume pot’s just been broken in a bit more.
I don’t see any reason why it wouldn’t be safe to use IEMs, the only thing is that I usually get some noise floor with IEMs on tubes (most of my IEMs are 16ohm impedance or less and high sensitivity).