Always good to see new big Tannoys out in the wild. If the current line was available when I bought my Canterbury SE, the GRF 90 would be atop my list. It looks like a replacement for the Yorkminster SE, but with
much improved aesthetics. Too bad it's "limited". The Yorkminster SE had better bass than Canterbury SE, btw.
I've always played mine loud. To be honest mine do display a minor rattle in 1 speaker on certain bass notes, but it's very rare. Sounds like a loose cable wire or other fixture rattling around. With all the acoustic energy coming from those cabinets and exciting god knows what in those "fancy" cabinets (yes these 15" drivers can easily energize a good sized room), it can be excused, so I never bothered to explore further. Been that way since day 1. Actually it may well be the damn variable port system -- good idea, not the best implementation.
That said, I've also experienced a tweeter diaphragm issue that developed over time on a my set of Kensington SE - that was more of a metallic ringing/static distortion on certain notes, and was more annoying. Probably something was going wrong with the voice coil. I got that one fixed with a replacement tweeter diaphragm, which fortunately is very small and simply bolts onto the back of the enormous driver (exact same part for Kensington, Yorkminster, Canterbury, and Westminster SE). I've also heard of the same happening to a pair of Dimension TD12 (same fix, slightly different part), and possibly a TD10. I
HOPE I can get an SE diaphragm in the future if I need one again!!
Unfortunately, relatively very few people have experience with these wonderful speakers. Here's mine:
I've always loved listening in very dim/dark lighting and seeing those gold rims outline the huge dual-concentric drivers. Man, I just love Tannoys.