The RF upgrade only comes with the 6x9 front woofer and small amp to provide extra oomph but the rears remains the same output wise.My Accord had the same setup but it seems like Toyotas rear sound stage seems to runs at fullrange giving you that oomph from the rear but somehow they balance the sound with the fronts.
Back to the Ascent (Premium)I had a look at the stock dash tweets and was pleasantly surprised how decent they looked ,by visual inspection they resemble silk dome tweets which probably why the tweets aren’t included in the RF upgrade.
A 4 channel plug’n’play amp upgrade with processing would definitely make a difference and I believe alot of folks will jump on it.All these JBL,H/K,BOSE stuff put in vehicles these days are decent for the average consumer but true audiophiles cringe at those systems.