As you know, the L-65 wasn't really designed to handle 200wpc but like virtually all JBLs they could play plenty loud being fed as little as 25-35 watts. For a smaller room they were fine, and in retrospect would have to say how loud does one need to go?
As for "whizz-boom" characteristics, yeah they could get too tizzy and forward with not careful tweaking of the L-Pads. I usually dialed mine no more than flat on both L-Pads, and sometimes even just a smidgen less on both.
Same with my 4430 Speakers, I run both L-Pads totally flat, and this seems to give overall best balance in my system. Same with my Mac Pre, rarely touch the tone controls. Maybe only at lower volumes might I dial up a little Loudness Compensation, or the Bass Dial just a tad.
Once I start ratcheting up the volume on the Bryston Monos, the bass and overall sound that the 4430 can provide is decent, and clean IMO. No, they don't go as low as some state of the art uber expensive monster speakers. Or as high as those which possessed the 077/2405.
One of the biggest downsides with such speakers as these two, and many others in the JBL family, were the Foam Surrounds. That sooner or later you will be replacing them, that's commonly a given and to be expected I guess.
Another minor downside with both L-65 and 4430 is their height. I always felt both benefitted by some degree of elevation.
The L-65 of course easier to deal with in this regard, whereas the 4430 is more difficult to handle-move, and do minor tweaking for positioning, becoming more of a 2-man job.