The first 100 pairs of VR-4jrs sold ~5 years ago are the only units that could ever even remotely be given the full bottom end descriptor. There was a very slight change so that they loaded and tuned ever so slightly different after the first 100 pairs. It leaned the bass out a touch more. I had one of the first 100 pairs on display for a long time. It was not boomy, but there was a slight difference when I put the second pair on display. With the latest generation of VR-4jr MKII, that's even less of a possibility.
As for models above the 4jr (VR-4 SR MKII, VR-5 SE, VR-7 SE, VR-9 SE, VR-11 SE) I can't even begin to address that one. Detail in the bass is one of their strong suits and effortless, smooth, yet detailed presentation is how I always feel listening to them.
For a floorstander with 7 inch woofers, the 4jr most definitely went a LOT lower than a lot of competitors and did it with authority. It was clean and balanced in its response up through the treble. I regularly measured flat below 25Hz in room with these speakers in a number of setups. I got flat to 20Hz with room gain in some setups.
The 4jrs, despite being a relatively small floorstander, played very, very big. They didn't really like being in a small room and would fill a room a lot larger than you would think and not run out of steam. In fact, they preferred a big room to really open up and bloom. I made them work in a 11X14 room once, but they weren't happy about it. To get the absolute best out of them, they were picky about placement. They would sound great no matter where you plunked them down. But they went to another level if you took the time to place them well. They also like a lot of power to really come alive. They'll work with just about anything, but the more juice you feed them, the better they like it. They were a bit more power hungry than the other models in the line-up.
No offense intended. But it sounds like a room interaction issue if the 4jr is being described as a boomy speaker, rather than a fault of the speaker itself. Or the speakers were in too small a room with an amp that didn't have enough control on the woofers. I played the 4jrs with a 211 SET for quite some time and it had the most seductive midrange you could imagine... but it sure didn't have what could be termed a visceral grip on the bottom end. But swapping out the SET for a solid state amp dramatically changed the character of the speaker....
I'm disappointed that the Von Schweikert "retail line" is no more. I'm even more disappointed that the VSX onwall speakers were discontinued before these latest announcements. It was all fantastic stuff that was an exceptional value for what you got. Albert sure knows how to make a speaker sound good.
I technically am still a dealer for Von Schweikert. But nothing above was intended in a commercial way. Just my personal thoughts having listened extensively for a number of years to VSA speakers. I'm a fan of Albert's work and have gotten many many hours of enjoyment listening to his creations.