The NBLs had floating nested boxes and the mid range drivers were on a sprung plate, so they needed securing. IBLs should be fine if just take normal precautions when moving any speaker.
If you get these set up well they can sound really good. You need to have them right up against a rear wall. They are not free space speakers. They are really fast and fun, but get the set up wrong and it;ll be like two transistor radios playing
Get a CB set up and experience a deal of what the original Naim was all about!
Best i heard my IBLs sound was on the end of a Nap160. Just enough warmth to compliment the slightly dry IBLs. Great speakers so long as they are hard up against a solid wall.