Von Schweikerts VR4 JR's and SR's?

Jek - To me they had more clarity, liveliness, musicality and resolved nuances of timbre and ambience better, with a warmer mid and a more dynamic yet controlled bass. Overall they strongly drew me into the music instead of one dominant feature of the music.

For what it is worth. I auditioned the Dali's and VSA Jr and Sr at same dealer. He and I both like the VSA better

The advice here is good, Cbucki sums it up very well. I auditioned both and went for the VR4SR's, largely based on having a very large room and liking the type of bass foundation that the larger woofers can provide. Used MK1 versions of both these are an excellent buy. AND for me it has caused a bad case of upgraditis that I am thoroughly enjoying in that the speaker just keeps getting better at approaching the pleasure of live music as I upgrade equipment and wire. I will bet that I will be satisfied with the Sr4's for at least a decade.

In terms of a sub, I run the Sr's both with and without a decent sub, and the woofers in the Sr's handle the bass exceptionally well. By contrast the sub sounds much less precise and dynamic, so when I run it I put it on crossing at 50HZ and very quietly. I find the sub useful only with some low organ and about three rock songs. The rest of the time the bass sounds better using only the SR's.
With a 20X40 room it would be worth considering the Sr if you want to listen at fairly loud levels occasionally - that is a big room! YMMV but I hate any sense of "shout" as speakers are driven hard and the SR's will fill the space without breaking a sweat. Guess you can always start with the jr's and if they totally please - stay there, else go to the SR's. Hope this helps.