Haven't tried the new ionics brush guys.
I use both monofilament & flocked rectangular vikans, i grind all the excess black plastic stock off though, only takes 2 mins & makes them smaller & ( i suppose ) a wee bit lighter. For me, i find these are the best all round domestic & small commercial wfp brushes.
Just a tip though, IMO you cannot compare the oval vikans to the newer rectangular ones as the latter are far, far better.
I've also tried one type of salmon (gaz) brush, it was totally useless & an unger brush which was ok' ish at the time.
Prior to these i was on oval vikans which came with my first poles jetted with fans & would never go back to either nor recomend either.
tony