The 3.5 was a clean, settled design which would have run longer, but for the advent of peak-intensive music. Wilson's Audiophile Recordings, complete with uncompressed cannons, along with other exhibition-style recordings simply over-drove the 3.5, well beyond what vinyl / analog ever could. The 3.5 drivers were by far the most robust we had ever used and we replaced, by far, more of them than any other model. That led to ported bass in upper models which, I believe, Jim developed extremely well. His alignments produce proper augmentation without the B&W bump and dump. But, as 3.5 fans know, the ported alignment introduces more phase shift and steeper low-end rolloff for a less natural result.
Each generation of each model makes incremental progress, led by its new driver development and then shaped by its enclosure and crossover implementation. The 3.5 was a breakthrough product and still holds its own today, nearly 35 years on.
I thank all of you for your continued appreciations.