Here's a followup/conclusion after 40+ hours of burn in. Sorry, long post coming.
tl;dr: These are great. I'm finding a little boominess at a specific frequency that I'm sure is a result of the room.
After adding sand to the bottom chamber these now weigh in at ~105lbs each
. They are on spikes, which are then on the little plate thingies that come with the spikes. I then had to attach some small furniture sliders to those to get them to move. It looks a little rinky dink, but seems to work well. We do need to be able to slide them easily, so I think that might be the permanent solution.
As for sound, wow. I was a little worried that I might not notice a big difference with these. Turns out that wasn't a problem at all. Seriously, I know many others on this forum have had this same experience, but these feel like orders of magnitude better than our previous setup. I can't imagine what the NX series must be like. My wife's jaw dropped when she heard them the first time as well.
In the first couple hours there was plenty of clarity in the upper registers, but they were a little thin in the midrange and virtually non-existent in the bass. I was in meetings from home most of the day while they played in the basement, and at some point at 5-10 hours in I started to notice some bass frequencies coming through the floor. As I checked in to them throughout the day the lower registers started to fill in more and more. I didn't really start listening to them critically until they had a full 24 hours in them at which point we basically spent all day in the basement listening to music and watching movies.
The bass is deeper and punchier than I anticipated. While they may not dig to subwoofer levels, "Intergalactic" by Beastie Boys (bass tip from Cheap Audio Man) was not lacking in low end, nor were any of the other bass heavy tracks I played. I turned off my sub when I started playing these and haven't missed it at all playing music. It will still be useful for movies, however.
After about 30 hours, I started getting better imaging and soundstage out of them, but that may also have been a result of me playing with the positioning a little. I found about 2' from the front walls with about 10-20deg of toe in worked in that room as it is right now (no treatments). I can't bring them out any more than that due to a doorway on the right side and furniture on the left. Vocalists started really locking in to the center at that point and I had to keep checking that I didn't have the center channel running.
Movies are just as impressive with a far better sense of clarity and location from voices, sounds and effects. The first movie I played was Pixar's Soul, which was a great showcase for them. I'm still running the original rears on this setup, so I know there is another level of immersion awaiting us along with getting two servo subs in the mix.
BTW, I'm running these from a Sony STR-ZA810ES AV receiver (good, not outstanding) that I picked up on an open box deal a couple years back and I'm using banana clips in the tube connectors for the time being until I can upgrade the speaker cables (currently, basic 14AWG zipcord style) for a more permanent tube connector setup. There is still a lot of improvement potential with these, and they still sound amazing.
The only downside I'm hearing is some boom in the bass at a specific frequency which I'm certain this is a room effect. I tried plugging the ports to see if that mitigated it, but that only helped a bit. I'm not adept enough to know what that frequency is, but I ordered a UMIK this morning so I can do some measurements with REW to target the offending frequencies (and what I'm sure are some holes in the response I'm not hearing) and start the process of getting some room treatments dialed in.
Finally, huge thanks to Danny and everyone here. I could not see myself paying retail for what speakers like these would go for, so without DIY communities like this we would have most likely missed out on this great experience.