i heard the double impacts a few years ago at a caf audio show, driven by lta electronics. i also heard the bmr towers this past november driven by less than sota electronics, imo. and, i had a pair of the bmr monitors in my large listening room for a few days (26x38x8.5), altho i had them crossed over to subs. i thought the d/i's were quite impressive. i think the bmr's are a bit more impressive. and, w/better amp/preamp, i think they'd be even better. if you have a pair of quality subs and actively cross them with the main speakers, i think the bmr monitors would offer performance very close to the bmr towers. in a big room like mine, it might still be advantageous to have the towers, even if crossed to subs.
of course, re philharmonic audio and tekton, that's just one person's opinion. both brands seem to get good reviews, and seem to offer real value for money.